taxonID	type	description	language	source
03C987A5FFA2FFE228225B2952B7B252.taxon	description	Morphological description — Annuals or perennials, mostly prostrate, cushion-forming or mat-like, sometimes in small and dense tufts. Stems often decumbent, rarely ascending, 2 – 60 cm high (Stellaria galianoi having greatest height), stems glabrous with few exceptions (S. apurimacensis) specially at nodes of leaves where hirsute hairs may occur, often glandular in surface; internodes hirsute or glabrous, short as in most of species and longer in S. apurimacensis and S. galianoi. Leaves mostly ovate, but linear to lanceolate in some species, 2 – 10 mm long, with acute or mucronate apex, usually hirsute near base, margins glabrous or ciliate, rarely lanuginose. Flowers solitary, only terminal, or in some species also axillary on short peduncles, with 5 sepals, free to base, mostly ovate to lanceolate, acute to acuminate in apex, base hirsute and stiff in texture, 1.8 – 5 mm long; petals mostly 5, rarely 4 or 3, showy and white or cream in colour and then usually bifid at apex, 10 – 15 mm long, or reduced to various degrees, mostly obtuse at apex, cream to translucent, and only up to 5 mm long and not overtopping sepals; stamens 5, often adherent to petals, filaments filiform and terete throughout (in all species for which descriptions are provided here), rarely thickened at base (P. keraiopetala, P. patagonica), in dioecious species sometimes a few staminodes present in pistillate flowers; ovary ovoid to globose, with trifid or rarely bifid styles, very rarely style single and unbranched (S. villasenori), in dioecious species often rudimentary pistillodes present in staminate flowers, these not more than 1 mm long and seedless. Capsule 1 – 12 - seeded; seeds more or less conspicuously tuberculate.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFA2FFE228225B2952B7B252.taxon	discussion	Notes — Until now there was no formal infrageneric name for the Plettkea clade. Sharples & Tripp (2019) annotated the lineage of Stellaria tetrasticha, corresponding to the Plettkea clade, in their trees with “ Plettkeae ” albeit without any reasoning for that name. The first infrageneric classification system by Fenzl (1840) recognized four entities, one of which, “ Eustellaria ”, was further subdivided. However, no specific nomenclatural rank was designated, until Pax & Hoffmann (1934) specified these entities as sections and subsections, respectively. We therefore suggest continuing the use of the sectional rank for the subdivision of Stellaria. No entity corresponding to a section Plettkea was included by Fenzl (1840) or Pax & Hoffmann (1934), so it is described here as a section of Stellaria. As Sharples (2019) and Sharples & Tripp (2019) already pointed out, more work needs to be done to develop a consistent infrageneric classification for Stellaria, which includes testing if existing sectional / subsectional names are validly published. Considering that S. graminea was designated as the neotype for the monophyletic genus Stellaria (Tikhomirov 2016), and that the name “ Eustellaria ” is not permitted under Art. 21.3 of the Code (Turland & al. 2018), the ‘ Larbreae’ clade (sensu Sharples & Tripp 2019) would become the typical S. sect. Stellaria (Sharples & Tripp 2019; Supplementary appendix S 9). Pax & Hoffmann (1934) validated the rank of Arenaria sect. Dicranilla (Fenzl) Pax & K. Hoffm. that was originally described by Fenzl (1840) based on A. dicranoides Kunth and A. bryoides, both described based on material from Mexico. In their treatment, Pax & Hoffmann (1934) also extended the concept of this section to include Andean species like A. bisulca (Bartl.) Fenzl & Rohrb., A. pycnophylloides Pax, A. alpamarcae A. Gray, A. boliviana F. N. Williams, A. pedunculosa Wedd., and A. pycnophylla Rohrb. However, the authors overlooked that these species do not match the original diagnosis by Fenzl (1840), who stated that the species of Dicranilla (Fenzl) Rchb. possess smooth, shiny, black seeds. On the contrary, members of the Andean Plettkea clade have tuberculate, brown seeds. Molecular phylogenetic data (T. Borsch, unpublished) further show that A. dicranoides belongs to the core Arenaria clade, underscoring that Pax & Hoffmann (1934) created an extended, morphologically heterogeneous and polyphyletic section. McNeill (1962) typified the genus name Dicranilla based on the section with Arenaria dicranoides, and commented on the misinterpretation of the seed characters by Pax & Hoffmann (1934). In summary, there was no name available for the ‘ Plettkea’ clade at the level of section. The publication by Timaná (2023), describing the new genus Baretia based on Pycnophyllum lanatum (Stellaria villasenorii), was received while correcting the proofs of this paper. We treat Baretia as a synonym here because to accept the new genus would make Stellaria paraphyletic.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFA0FFE32BAF58C95094B752.taxon	materials_examined	– Lectotype (designated here): Peru, 1838 – 1842, Wilkes Expedition s. n. (GH 00037630 image!; isolectotype: NY 00342438 image!). – Fig. 1 A.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFA0FFE32BAF58C95094B752.taxon	description	Morphological description — Perennial herb, caespitose forming pulvinate dwarf cushions 2 – 4 cm high and 8 – 20 cm in diam.; root woody. Stems short or elongated erect in young plants becoming decumbent later on, usually covered by old foliage; internodes 1 – 2 mm long, with a scarce indumentum of trichomes <0.1 mm. Leaves imbricate, lamina ovate-lanceolate, 4 – 7 mm long and 0.9 – 1.2 mm wide, longitudinally striate, midrib prominent on underside, margins thick, delicately folded toward adaxial surface, glabrous in distal part and at acuminate apex, turning ciliate toward base, where hairs can be dense (1 – 3 mm long). Plants bisexual-hermaphrodite. Flowers on 2 – 6 mm long, glabrous peduncles, terminal and axillary; perigynous, oblong, c. 4.5 mm long and 1.5 – 2.5 mm wide; calyx cylindrical-oblong; sepals 5, imbricate, oblong, 3 – 4 mm long and 1 – 2 mm wide, smooth, glabrous on surface and margins, apex acute-acuminate, usually folded and forming a cone-like cylinder that covers capsule; petals 5, strongly reduced, translucent, ovate, apex obtuse, c. 0.8 mm long and 0.5 mm wide; stamens 4 or 5, episepalous, 0.8 – 1.1 mm long; ovary cylindrical-turbinate, 0.6 – 0.9 mm long and 0.4 – 0.6 mm wide, style 3 - fid, stigma aciculate, terete. Capsule ovoid, c. 1.5 mm long, containing 5 – 8 seeds, these globular in shape, c. 0.2 mm wide and 0.3 mm long; testa pale brown and cells with whitish stellate tubercles.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFA0FFE32BAF58C95094B752.taxon	discussion	Notes — The specimen chosen as the lectotype was likely examined by Asa Gray for the description of the species. Assuming it came from the same gathering, the specimen in NY (NY 00342438) with a label indicating the years 1838 – 1842 and “ Peru ” would be an isolectotype. The identity of further historical material annotated as isotypes of Arenaria alpamarcae available through JSTOR Global Plants (JSTOR 2023) is less clear. The locality information on a specimen in US (US 00103277) given as “ Alpamarca above Obrajillo and Banos [possibly Baños] ” corresponds to the highlands of the Lima department in central Peru, which is possibly a different place. A second specimen in NY (NY 00342437) lacks collector and geographical information and a specimen in P (P 00335842) has just a label indicating the years 1838 – 1842 but lacks any collector or locality data beyond “ Peru ”.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFA0FFFC2822590951BBB692.taxon	materials_examined	– Lectotype (designated here): Bolivia, Prov. Larecaja, viciniis Quiabaya via ad Tacacoma, 20 May 1860, G. Mandon 954 (K 000471618 image!; isolectotypes: F 0053255 image!, P 00335843 image!, P 00335844 image!, P 00335845 image!, P 01902983 image!, S-R- 351).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFA0FFFC2822590951BBB692.taxon	description	Morphological description — Annual herb, sometimes forming large mats or carpets, 5 – 8 cm high and up to 30 cm in diam.; roots fibrous. Stems erect or decumbent, diffuse, usually loose, internodes 4 – 6 mm long, glabrous. Leaves opposite, lamina ovate, 2.5 – 3.5 mm long and 1 – 1.5 mm wide, surface glabrous on both sides, bright green to yellowish with age, margins bearing c. 0.1 mm long trichomes, midrib imposed on adaxial side, base petiolate and hirsute, apex acuminate. Plants bisexual-hermaphrodite. Flowers on short 1 – 4 mm long glabrous peduncles, terminal; perigynous, campanulate to subglobose, 4 – 5 mm long and wide, crateriform,; sepals 5, imbricate, oblong, slightly involute, apex obtuse-acute, base attenuate, 3 – 4 mm long and c. 2 mm wide, bright green to green-yellowish with age, glabrous to rarely covered by thin white trichomes (<0.1 mm long) at margins; petals 5, ovate, translucent to pale yellowish, rarely whitish, 1 – 1.8 mm long and 0.5 – 1 mm wide, apex rounded to obtuse; stamens 5, episepalous, 0.7 – 1 mm long; ovary ovoid, 0.8 – 1.1 mm long, style 3 - fid, stigma terete to aciculate. Capsule ovoid, c. 2 mm long, containing 4 – 6 seeds, these ovate, c. 0.3 mm long; testa maroon, tuberculate.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFA0FFFC2822590951BBB692.taxon	vernacular_names	Vernacular name — Wanupi Tika, given in Quechua language (Zoilita Salazar Patiño, Arequipa, pers. comm.).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFA0FFFC2822590951BBB692.taxon	discussion	Notes — Paul Rohrbach (Berlin) aimed at a taxonomic synthesis of Andean Caryophyllaceae but died at an early age, so Garcke arranged to have his manuscript published in Linnaea. Rohrbach himself wrote (p. 184) “ … so bildet die Mandon’sche Sammlung aus Bolivia den Kern des mir von dort vorliegendem Materials. Ich habe dieselbe in ziemlich gleicher Vollständigkeit in drei Herbarien, dem des k. k. botanischen hofkabinets zu Wien, dem De’Candolleschen und dem des Grafen Franqueville gesehen; … ” in the protologue, Rohrbach (1872) mentioned “ Mandon 954! ” but without designating any particular specimen as a type. There is no specimen in W because Mandon material appears to have been lost due to a fire in the Second World War (Heimo Rainer, pers. comm. and as stated in https: // www. nhm-wien. ac. at / en / research / botany / collections / lost _ families).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBFFFFC2B8558C95716B7B2.taxon	materials_examined	Holotype: Peru, Apurimac, Cotabambas, Haquira, NW of Haquira, 4525 m, 28 Mar 2017, D. Montesinos & D. Cornejo 5194 (HSP [HSP- 9443!]; isotypes: B [B 10 0761536!], CUZ!, F!, USM!).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBFFFFC2B8558C95716B7B2.taxon	diagnosis	Diagnosis — The new species is distinguishable by its rosette or small mat, ovate leaves, apetalous flowers and short internodes.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBFFFFC2B8558C95716B7B2.taxon	description	Morphological description — Annual herb, densely ramified at base, forming cushions c. 2 cm high and 6 – 10 cm in diam.; roots fibrous. Stems decumbent or creeping, 4 – 6 cm long, often densely branched and covered by older leaves in central and lower parts; internodes 4 – 10 mm long, glabrous. Leaves opposite, petiolate, lamina elliptical-lanceolate, 2 – 3 mm long and 0.8 – 1.2 mm wide, sparsely pilose along margin, trichomes 0.1 – 0.3 mm long, acuminate, plain or curved, thin, slightly involute, glabrous on both sides, midrib protuberant on underside. Plants bisexual-hermaphrodite. Flowers on rigid or slightly curved 2 – 5 mm long glabrous peduncles, terminal; perigynous, 2.5 – 3.5 mm long and 1.5 – 2.2 mm wide, calyx campanulate, glabrous; sepals 5, imbricate, slightly involute, lanceolate-ovate, cupuliform at base, apex acuminate, glabrous, 2 – 3 mm long and 1 – 1.5 mm wide, pale green to yellowish; petals 5, translucent, ovate, 0.8 – 1.2 mm long and 0.4 – 0.6 mm wide, apex rounded; stamens usually 10, episepalous, filaments 0.3 – 0.4 mm long; ovary ovoid, 0.4 – 0.6 mm long and 0.3 – 0.5 wide; style 3 - fid, curved, glandular, 0.3 – 0.5 mm long. Capsule ovoid, glabrous, c. 2.2 mm long, containing 4 – 6 seeds, these roundish to ovate, 0.4 – 0.5 mm long and 0.3 – 0.4 mm wide; testa pale brown, cells with tuberculate and stellate protuberances of c. 50 µm in diam.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBFFFFC2B8558C95716B7B2.taxon	etymology	Etymology — The epithet name is allusive to the Apurimac department located in S Peru, the site of the type locality.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBFFFFC2B8558C95716B7B2.taxon	vernacular_names	Vernacular name — Hatun Yuraq Tika, given in Quechua language (Zoilita Salazar Patiño, Arequipa, pers. comm.).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBFFFFC2B8558C95716B7B2.taxon	discussion	Notes — Stellaria apurimacensis is morphologically similar to S. galianoi but differs by the internode length (4 – 10 mm vs. 2 – 15 mm in S. galianoi), smaller leaves (2 – 3 mm long and 0.8 – 1.2 mm wide vs. 3 – 5 mm long and 1.4 – 1.8 mm wide in S. galianoi), shorter peduncles (2 – 5 mm vs. 7 – 15 mm in S. galianoi), wider sepals (1 – 1.5 mm vs. 0.8 – 1 mm in S. galianoi) and smaller seeds (0.4 – 0.5 mm long vs. 0.6 – 0.8 mm long in S. galianoi). Stellaria apurimacensis differs from S. macbridei by the longer internodes (4 – 10 mm vs. 3 – 4 mm in S. macbridei), smaller leaves (2 – 3 mm long and 0.8 – 1.2 mm wide vs. 5 – 7 mm long and 2 – 2.5 mm wide in S. macbridei) and from S. utcubambensis by the weaker stems and leaves (vs. robust in S. utcubambensis).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBFFFFD28785E2953CCB2B2.taxon	materials_examined	– Lectotype (designated here): Peru, Cobradillo [illegible, possibly misspelled as Obrajillo, town located in Canta, Lima], 1821, Haenke s. n. (GOET 000573!). – Fig. 1 B.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBFFFFD28785E2953CCB2B2.taxon	description	Morphological description — Perennial herb, caespitose, forming cushions or small mats, c. 4 cm high and up to 20 cm in diam.; root woody. Stems procumbent, numerous, forming a densely congested structure, with 6 – 10 cm long branches; internodes short, c. 0.1 mm long, glabrous. Leaves imbricate dense, rigid, lamina thick, ovate, 4 – 7 mm long and 1 – 1.2 mm wide, acute or slightly mucronate at apex, base scarcely attenuated, margins glabrous, also at base, margins involute, midrib prominent on underside. Plants bisexual-hermaphrodite. Flowers on 2.5 – 3 mm long, glabrous peduncles, terminal and axillary; perigynous, oblong, 3.5 – 4.5 mm long and 1 – 1.5 mm wide; calyx cylindrical-turbinate; sepals 5, imbricate, lanceolate, involute, 2 – 2.5 mm long and 1 – 2 mm wide, pale green to yellow, glabrous on surface and margins, apex acute-acuminate, folded and forming a cone-like cylinder that covers capsule; petals 5, strongly reduced, translucent, ovate, apex obtuse, 0.8 – 1 mm long and 0.5 – 0.7 mm wide; stamens 4 or 5, episepalous, 0.8 – 1.1 mm long; ovary cylindrical-turbinate, 0.8 – 1.2 mm long and 0.8 – 1.1 mm wide, style 3 - fid, stigma aciculate. Capsule narrowly ovoid, shorter than calyx when mature, 1.5 – 2 mm long, opening with 6 valves, containing 6 seeds, these suborbicular, lentiform, 0.2 – 0.3 mm in diam.; testa pale brown, bearing whitish protuberances.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBFFFFD28785E2953CCB2B2.taxon	distribution	Distribution — The species is endemic to Peru (Cano & Sánchez 2006) and is known to occur in Áncash, Huánuco, La Libertad and Junín departments according to the material revised and at altitudes of 3900 – 4500 m.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBFFFFD28785E2953CCB2B2.taxon	etymology	Etymology — The epithet congesta refers to the uniform and compact growth of the species.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBFFFFD28785E2953CCB2B2.taxon	discussion	Notes — The specimen at GOET has the annotation “ rel. Haenk. II, 12 (cum descriptione) ”, which indicates that the specimen may have been used to make a description.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBEFFFE2BAF5D29519FB552.taxon	materials_examined	– Holotype: Peru, Morococha, A. Raimondi 8392 (B †). – Neotype (designated by Timaná 2017: 6): Peru, Lima, Huarochirí, Paso de Anticona, Ticlio, 4850 m, 16 Dec 1998, Timaná & Tate 3767 (USM; isoneotype: MO- 1100075!).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBEFFFE2BAF5D29519FB552.taxon	description	Morphological description — See Timaná (2005).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBEFFFE2BAF5D29519FB552.taxon	distribution	Distribution — The species is found in highland passes in Andean mountainous ranges between the departments of Puno and Lima in Peru at altitudes of 4800 – 5200 m.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBEFFFE2BAF5D29519FB552.taxon	discussion	Notes — According to Timaná (2017), this distinctive species, has tetramerous flowers and 2 free styles. The species, originally described by Mattfeld (1934) as Plettkea cryptantha, is characterized by decussate sepals with the inner pair shorter and non-ciliate as opposed to the outer pair. Molinari-Novoa (2016) described the new combination Pycnophyllopsis cryptantha (Mattf.) Molinari, without studying any type specimen; the holotype was destroyed and no neotype had yet been selected. Timaná (2017) solved this by selecting a new type for the species based on a specimen collected near the type locality by Raimondi in Lima. Later, Sharples & Tripp (2019) stated that Greenberg & Donoghue (2011) recovered a sample of Pycnophyllopsis cryptantha (Mattf.) Timaná from Peru as embedded within core Stellaria. The trnL-F sequence available in GenBank is resolved as sister to CAR 431 (Supplementary appendix S 6) that is the representative of S. cryptantha in our analysis.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBDFFFE2B855B095154B1B2.taxon	materials_examined	– Lectotype (designated here): Peru, Junín, Tarma, La Oroya, encima de Tarma en el camino a La Oroya, 4000 m, A. Weberbauer 2542 (MOL [MOL 00000453!]).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBDFFFE2B855B095154B1B2.taxon	description	Morphological description — Perennial herb, diffuse caespitose, cushions 5 – 12 cm in diam.; root woody. Stems subwoody, lower parts clothed with a greyishgreen thick bark, or very minutely ridged-reticulated, prostrate, sometimes rooting at nodes, 3 – 6 cm long, internodes 0.1 – 0.5 mm long, glabrous or with sparse slightly yellowish-whitish pubescence, trichomes 1 – 2 mm long. Leaves opposite, sessile; lamina lanceolate or ovate or rarely linear-lanceolate, fleshy or rarely membranous, thick, apex acute or mucronate, 5 – 10 mm long and 2 – 5 mm wide, hirsute near base and midvein, margin slightly hairy, midrib prominent on underside. Plants bisexual-hermaphrodite. Flowers subsessile or on short up to 0.5 mm long, glabrous peduncles, terminal and axillary; perigynous, cylindrical-oblong, 3.5 – 4.5 mm long and 1 – 1.8 mm wide; calyx cylindrical-turbinate; sepals 5, imbricate, ovate-oblong, slightly involute, yellow, 3 – 4 mm long and 1 – 1.5 mm wide, glabrous on surface but margins densely ciliate, apex acute-attenuate, folded and forming a narrow cylinder that covers capsule; petals 5, strongly reduced, yellowish to translucent, ovate, apex obtuse, 0.8 – 1.2 mm long and 0.3 – 0.5 mm wide; stamens 4 or 5, episepalous, 1.8 – 2.1 mm long; ovary ovoid-turbinate, 0.4 – 0.7 mm long and 0.4 – 0.6 mm wide, style 3 - fid, stigma aciculate. Capsule subglobose, dehiscent with six valves, ovate-oblong, 1.3 – 1.7 mm long and 1.2 – 1.5 mm wide, containing 2 – 4 seeds, these lenticular, 0.7 – 1 mm in diam.; testa dark brown, bearing brown tubercles.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBDFFFE2B855B095154B1B2.taxon	distribution	Distribution — Central Peru, in Junín and Huánuco departments, at altitudes of 4000 – 4400 m.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBDFFFF2B855C29571CB2D2.taxon	materials_examined	Holotype: Peru, Cusco, Urubamba, Urubamba, Puerto Yanamayo, Patacancha, road to Ocobamba, 4440 m, 3 Apr 2016, D. Montesinos 4572 (HSP [HSP- 9443!]; isotypes: B [B 10 0766217!], O [O- 227237!], USM!).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBDFFFF2B855C29571CB2D2.taxon	diagnosis	Diagnosis — This species is easily distinguished by its long internodes (2 – 15 mm long), leaf laminas bearing white protuberances, absent characters in other species of Stellaria sect. Plettkea.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBDFFFF2B855C29571CB2D2.taxon	description	Morphological description — Perennial herb, forming diffuse mats, 4 – 8 cm high and 20 – 60 cm in diam.; roots fibrous. Stems decumbent or creeping 8 – 25 cm long, densely ramified at base and along whole length, glabrous, or nearly so (scarcely covered with minute papillae), covered by older leaves in central and lower parts; internodes 2 – 15 mm long. Leaves opposite, sessile; lamina oblanceolate-oblong to gladiate, plain or curved, nearly involute, glabrous on both sides, 3 – 5 mm long and 1.4 – 1.8 mm wide, midrib protuberant on underside, margin from base to mid of lamina with 4 – 7 multicellular pilose hairs (0.3 – 1 mm long, 6 – 14 cells) born on protuberances, usually persistent on older leaves; base truncated and apex aristulate; leaves pale green to yellow-brownish with age. Plants bisexual-hermaphrodite. Flowers perigynous, on rigid 7 – 15 mm long and glabrous peduncles, terminal, 2.2 – 3 mm long and 3 – 5 mm wide; calyx campanulate, glabrous; sepals 5, lanceolate, slightly involute, cupuliform at base, apex apiculate-aristulate, glabrous, 1.8 – 2.4 mm long and 0.8 – 1 mm wide, pale green to yellowish; petals 5, white, subglandular, ovate, with revolute obtuse apex, 2 – 3 mm long and 1 – 1.5 mm wide; stamens usually 10, episepalous, filaments often curved toward centre of flower, 0.3 – 0.5 mm long; anthers roundish to elliptical, reniform, yellowish and 0.15 – 0.3 mm long; style 3 - fid, curved, glandular, pistil 0.5 – 0.7 mm long; stigma papillate or glandular; ovary cylindrical-ovoid, 0.7 – 1.1 mm long and 0.8 – 1.1 mm wide. Capsule ovoid, glabrous, c. 1.8 mm long and 2.5 mm wide, containing 10 – 12 seeds, these ovate or roundish, 0.6 – 0.8 mm long and 0.4 – 0.6 mm wide; testa brown, grooved, cells with bulgy stellate protuberances.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBDFFFF2B855C29571CB2D2.taxon	etymology	Etymology — The specific epithet refers to Prof. Washington Galiano (1950 –), for his devoted career on studying the floristic diversity of the Cusco department in S Peru.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBDFFFF2B855C29571CB2D2.taxon	discussion	Notes — Stellaria galianoi is most likely monophyletic and is phylogenetically rather isolated among other members of the Plettkea clade (Fig. 3, 4). This species has the longest internodes of vegetative stems across the Plettkea clade, eventually, in the uppermost the internode is long, sometimes as reaching 1.5 cm. This character makes it easy to recognize among the apetalous taxa of Andean Stellaria. The new species differs from the known South American species of Arenaria by its leaf form and by the densely tuberculate seeds. Furthermore, S. galianoi differs from S. apurimacensis by the internode length (2 – 15 mm vs. 4 – 10 mm in S. apurimacensis), larger leaves (3 – 5 mm long and 1.4 – 1.8 mm wide vs. 2 – 3 mm long and 0.8 – 1.2 mm wide in S. apurimacensis), longer peduncles (7 – 15 mm vs. 2 – 5 mm in S. apurimacensis), narrower sepals (0.8 – 1 mm vs. 1 – 1.5 mm in S. apurimacensis) and larger seeds (0.6 – 0.8 mm long vs. 0.4 – 0.5 mm long in S. apurimacensis). Stellaria galianoi differs from S. andina in the leaf form (oblanceolate-oblong to gladiate vs. ovate in S. andina) and longer peduncles (7 – 15 mm vs. 1 – 4 mm in S. andina).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBCFFF828225C8951D7B712.taxon	materials_examined	– Holotype: Bolivia, zwischen Palca und La Paz, an Felsen, 4800 m, Apr 1908, K. Pflanz 233 (B †). – Neotype (designated by Timaná 2017: 6): Bolivia, La Paz, Murillo, Cordillera Real, road to nevado Chacaltaya, N of Milluni crossing E of Lake Milluni along roadsides, 4600 – 4900 m, 25 Jan 2000, Timaná 3804 (LPB 0000524; isoneotypes: BM, K, LL, MCSN, MICH, USM).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBCFFF828225C8951D7B712.taxon	description	Morphological description — See Timaná (2005).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBCFFF828225C8951D7B712.taxon	distribution	Distribution — The species is endemic to Bolivia and based on two collections and according to Timaná (2017), it is known to occur at altitudes of 4600 – 5100 m.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBCFFF828225C8951D7B712.taxon	discussion	Notes — The neotype located at the Herbario Nacional de Bolivia, Universidad Mayor de San Andrés (LPB) was designated by Timaná since the original material collected by K. Pflanz 223 was lost (B †). According to Timaná (2017), Pycnophyllopsis keraiopetala (now Stellaria keraiopetala) is the only species with trimerous petals and stamens, although tetramerous and pentamerous forms are also found (sometimes all three forms in the same plant). Stellaria keraiopetala is the sister to S. weberbaueri, and both share the habit of dense small cushions with stems covered by overlapping leaves. Stellaria keraiopetala and S. weberbaueri appear to be geographically vicariant species due to its distribution in the highest parts of the Andes in Bolivia and Peru, respectively.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBBFFF82B85594956AEB6D2.taxon	materials_examined	– Lectotype (designated by Timaná 2017: 8): Peru, Quebrada de l’Obrachillo, s. d., Haenke s. n. (PR not seen; isolectotypes: GOET 000715!, HAL 0117903 image!). = Cherleria bisulca Bartl. in Presl, Reliq. Haenk. 2: 12. 1831, syn. nov. ≡ Arenaria bisulca (Bartl.) Fenzl ex Rohrb in Linnaea 37: 248. 1872. – Type: Peru, Peru, 1791, T. P. X. Haenke s. n. (HAL 01178886 [image!]).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBBFFF82B85594956AEB6D2.taxon	description	Morphological description — See Timaná (2005).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBBFFF82B85594956AEB6D2.taxon	distribution	Distribution — The species inhabits highland plateaus of the central Andes in Peru, at altitudes of 4660 – 4800 m, in the Lima and Junín departments. The environments where the species grows are highland plateau Andean grasslands with rocks, with template and harsh wind conditions.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBBFFF82B85594956AEB6D2.taxon	discussion	Notes — Mattfeld (1934) tentatively included the species described by Bartling (1831) under the genus Cherleria into Plettkea. Mattfeld considered the characters mentioned in the original description as he had no access to specimens. Rohrbach (1872) transferred the species to Stellaria without further reference. Timaná (2017) encountered the Haenke specimen at PR and respective duplicates at HAL and GOET and argued that the species belongs to Pycnophyllopsis. The examination of the type specimen at GOET showed the presence of hirsute leaf margins, apetalous flowers supporting the position in the Plettkea clade. In the ITS tree specimen CAR 912 of S. laevis is resolved as sister to S. cryptantha, albeit with low support (it was not possible to amplify plastid regions in this specimen). The examination of the type specimen further revealed the similarity with Arenaria bisulca (Bartl.) Fenzl & Rohrb. A species also described by Bartling (1831) under Cherleria, which is therefore put into synonymy in this study. Also, Zanotti & al. (2022) discussed if S. laevis could be closely related to Arenaria bisulca, an opinion to which we agree with due to the exact match of morphological characters. Moreover, S. laevis appears to be morphologically similar to S. andina having several differences such as the habit and growth form (loose mat-forming herb vs. weak herbs S. andina), leaf form and stiffness (rigid in S. laevis vs. weak in S. andina) and minor flower characteristics. Sequence data of ITS resolve S. laevis as part of subclade A within the Plettkea clade of Stellaria (Supplementary appendix S 9).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBBFFF92807588952C8B692.taxon	materials_examined	– Holotype: Peru, Lima, Río Blanco, 3000 m, prostrate on upland slopes, Macbride 812 (F [F 0042702 F image!]; isotypes: NY [NY 00342439 image!], US [US 00103284 image!]). – Fig. 1 D.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBBFFF92807588952C8B692.taxon	description	Morphological description — Perennial herb, individual stems visible (not caespitose); root thick, reaching c. 4 cm deep. Stems 7 – 12 per individual, decumbent to ascending, 3 – 5 cm long; internodes 3 – 4 mm long, densely hirsute near nodes; trichomes irregularly shaped, multicellular, uniseriate, 0.5 – 1 mm long. Leaves, with broad and hirsute petioles, alternate; lamina oblong, 5 – 7 mm long and 2 – 2.5 mm wide, subcoriaceous or membranous, thickened at base, shiny, glabrous on both sides, thin, margins ciliate or hairy-ciliate, apex acuminate and slightly involute, only midrib hirsute. Plants bisexual-hermaphrodite. Flowers perigynous, on 1 – 1.8 mm long ciliate peduncles, axial and terminal; cylindrical-oblong, 2.5 – 3 mm long and 1.2 – 1.8 mm wide; calyx cylindrical-turbinate, thicker at base, crateriform; sepals 5, imbricate, narrowly lanceolate, 2 – 2.3 mm long and 0.4 – 0.6 mm wide, glabrous on surface, light green to bright yellow, apex acute-attenuate, involute, folded and forming a narrow cylinder that covers capsule; petals 5, reduced, translucent-stramineous, ovate, apex obtuse, 1 – 1.3 mm long and 0.2 – 0.4 mm wide; stamens 4 or 5, episepalous, 1 – 1.5 mm long; ovary ovoid-turbinate, 0.4 – 0.8 mm long and 0.6 – 0.8 mm wide, style 3 - fid, stigma aciculate. Capsule ovoid, 0.9 – 1.2 mm long containing 4 seeds, these orbicular, 0.2 – 0.3 mm in diam., testa reddish-maroon and shiny, cells bearing light maroon tubercles.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBBFFF92807588952C8B692.taxon	etymology	Etymology — The specific epithet refers to J. F. Macbride (1892 – 1976), American botanist who provided the last comprehensive revision for Stellaria and Arenaria from Peru and also was one of the authors who originally described this species.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBBFFF92807588952C8B692.taxon	discussion	Notes — Macbride (1936) mentioned that Stellaria macbridei has similarities with S. congesta but differs from that species by the tuber-like root and the small erect habit. Other differences include suboblong leaf form (ovate in S. congesta) and the narrowly lanceolate sepals (lanceolate in S. congesta). The two sequenced specimens are sisters and form a distinct lineage within the Plettkea clade in both the plastid and nuclear trees (Fig. 3, 4) underscoring the identity of S. macbridei as a distinct and eventually monophyletic species.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBAFFF92BAF58C951AEB312.taxon	materials_examined	– Lectotype (designated by Molinari-Novoa 2016: 276): Peru, Áncash, Cordillera Blanca, 4500 m, 14 May 1903, A. Weberbauer 2975 (MOL 00000509!).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBAFFF92BAF58C951AEB312.taxon	description	Morphological description — See Timaná (2005).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBAFFF92BAF58C951AEB312.taxon	distribution	Distribution — Huascarán National Park in Áncash department, central Peru, at altitudes of 4500 – 4800 m (Timaná 2017).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBAFFF92BAF58C951AEB312.taxon	discussion	Notes — Muschler (1911: 458) described Pycnophyllum macrophyllum based on the leaf shape and few relevant flowers characters. Molinari-Novoa (2016) simply transferred the species to Pycnophyllopsis referring to Timaná (2005) who recognized Pycnophyllopsis s. l. (including Plettkea) as distinct from Pycnophyllum without any own analysis of plant material. According to Timaná (2017), Stellaria macrophylla differs from S. cryptantha in the number of floral parts: S. macrophylla is pentamerous with three free styles while S. cryptantha a tetramerous species with two free styles. In addition, the leaves of S. macrophylla are slightly narrower toward the apex, where in S. cryptantha these are more triangular. The only collection known is the type specimen at MOL. This specimen has no seeds which was also confirmed by physical examination (G. Tello, Lima, pers. comm.). Therefore, it is unclear from where Muschler took the information on seeds, which does not even correspond to specimens of the Plettkea clade and therefore could be wrong.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBAFFF92BAF5D4950F7B792.taxon	materials_examined	– Lectotype (designated by Timaná 2017: 6): Argentina, Patagonia Andina, territorio Chubut, Meseta Chala, c. 1300 m, 5 Dec 1908, Skottsberg 606 (S [S 05 - 10321 image!]; isolectotypes: LD [LD 1418578 image!], SG [SGO 000001982 image!]).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBAFFF92BAF5D4950F7B792.taxon	description	Morphological description — See Timaná (2005).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBAFFF92BAF5D4950F7B792.taxon	distribution	Distribution — Patagonian plateaus in Argentina, at altitudes of 800 – 1300 m, in open slopes, rocky and very windy.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBAFFF92BAF5D4950F7B792.taxon	etymology	Etymology — In allusion to the Patagonia region in Argentina where the species grows.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBAFFF92BAF5D4950F7B792.taxon	discussion	Notes — The species shows morphological affinities to Stellaria sect. Plettkea, such as short stems bearing short internodes, densely appressed leaves with ciliate margins, apical, solitary flowers, shortly pedunculate, bearing five sepals and an equal number of reduced petals, so to be placed under Stellaria. The type specimen has no seeds and the protologue does not mention any seed characters.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBAFFFA282259C95223B7D2.taxon	materials_examined	– Lectotype (designated here): Bolivia, La Paz, Ravin de Chuquiaguillo, 1851, H. Weddell s. n (P [P 00274242 image!]). – Fig. 1 E.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBAFFFA282259C95223B7D2.taxon	description	Morphological description — Annual herb, forming small caespitose tufts, 1 – 2 cm high and 2 – 3.5 cm in diam.; roots fibrous. Stems few, often further ramified at base; internodes 1 – 4.5 mm long, glabrous. Leaves opposite, sessile; lamina oblong-ovate, 4 – 6 mm long and 1 – 1.6 mm wide, thin, to some extent curved at tip, rarely involute, scarcely covered by tomentulose hairs on upper- and underside, midrib inconspicuous; base truncated and apex acute, margin tomentulose with multicellular hairs 0.1 – 0.25 mm long (occasionally mammillate and without distinct trichomes), usually persistent on older foliage; leaves pale green to yellow-brownish with age. Plants bisexual-hermaphrodite. Flowers perigynous, on rigid 8 – 11 mm long peduncles covered with minute papillae, terminal, ovoid, 2 – 2.6 mm long and 1 – 1.6 mm wide; calyx cylindrical-campanulate, crateriform; sepals 5, ovate, 1.8 – 2.4 mm long and 0.8 – 1 mm wide, slightly involute, green to yellowish-translucent with age, cupuliform at base, apex acute, mucronate, pale green to yellowish, surface glabrous, margins with scattered papillae, 0.08 – 0.1 mm long; petals 5, reduced, light green, ovate, obtuse, equalling sepals or shorter, 1.2 – 1.5 mm long and 0.6 – 0.8 mm wide; stamens 5, very short, 0.2 – 0.4 mm long, episepalous; style 3 - fid, glandular, 0.25 – 0.35 mm long, aciculate; ovary ovoid, 0.2 – 0.5 mm long and 0.3 – 0.5 mm wide. Capsule ovoid, c. 1 mm long, glabrous, containing 2 – 5 seeds, these orbicular, 0.6 – 0.8 mm in diam., testa brown-yellowish, granulate.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBAFFFA282259C95223B7D2.taxon	distribution	Distribution — Based on two collections (DBMT 5395 b, 4565), Arenaria pedunculosa is located at the lower slopes SE of Ticsani volcano (Moquegua department), on volcanic pumice soils at altitudes of 4500 – 4820 m. Flowers and fruits were observed between February and March. In Bolivia the species is known only from the type collection, and a search of material at LPB in 2019 provided no evidence that the species has been collected again.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBAFFFA282259C95223B7D2.taxon	vernacular_names	Vernacular name — Jiska Volcanqura Panqara, given in Aymara language (Kent Chicalla, Moquegua, pers. comm.).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFBAFFFA282259C95223B7D2.taxon	discussion	Notes — Even though the intense survey done at the herbaria mentioned in the methods, no specimens have been found as additional collections for Bolivia, but two specimens have been found from the Moquegua department in Peru.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB9FFFA2B85598953CEB232.taxon	materials_examined	– Holotype: Peru, Lima, Huarochirí, Paso de Anticona, Ticlio, 4850 m, 16 Dec 1998, Timaná & Tate 3768 (USM!; isotypes: BM, F, K!, LL, LPB [LPB 0000525], MICH).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB9FFFA2B85598953CEB232.taxon	description	Morphological description — See Timaná (2005).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB9FFFA2B85598953CEB232.taxon	distribution	Distribution — According to Timaná (2017), the species should be distributed in the boundary between the Peruvian departments of Lima and Junín, at altitudes of 4300 – 4900 m, but should also be present in the Áncash department (Huascaran National Park) at an altitude of c. 4800 m. However, no further specimens in addition to the type appear to be known.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB9FFFA2B85598953CEB232.taxon	discussion	Notes — The characters such as the imbricate, lanceolate, stiff leaves, with ciliate margin, the short flower peduncles and the staminoid petals are considered to provide evidence for the inclusion of the species in the Plettkea clade.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB9FFFA2B855CA950CEB3B2.taxon	materials_examined	Lectotype (designated here): Peru, 1839 – 1840, C. Gay 1818 ([P (P 00335797)]; isolectotype: ([MO- 840929]).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB9FFFA2B855CA950CEB3B2.taxon	description	Morphological description — Perennial herb, varying from few stems up to 50 cm long to forming dense mats 2 – 4 cm high; root woody. Stems decumbent, creeping and with branches distinctly shorter than stems, bearing remains of old foliage along stems; internodes 1 – 1.5 mm long; sparsely pubescent with erect 0.1 – 0.3 mm long trichomes. Leaves alternate, lamina lanceolate to linear-lanceolate, 4 – 6 mm long and 1 – 1.5 mm wide, coriaceous, with acuminate to subaristate apex, densely ciliate near truncate base. Plants bisexual-hermaphrodite. Flowers perigynous, terminal, on hirsute, thick, 3.5 – 4 mm long peduncles, but these hidden by uppermost leaves; calyx cylindrical to rarely subcampanulate, 3.5 – 4 mm long and 1.5 – 2 mm wide, crateriform, usually thickened at bottom; sepals 5, lanceolate, cupuliform at base, involute, 3 – 3.5 mm long and c. 0.8 mm wide, apex acute, light green to pale yellowish, glabrous on surface and along margins; petals 5, strongly reduced, translucent, ovate, apex obtuse, 1.2 – 1.6 mm long and 0.7 – 0.8 mm wide; stamens 4 or 5, episepalous, 1.1 – 1.3 mm long; ovary cylindrical-turbinate, 0.5 – 0.7 mm long and 0.6 – 0.8 mm wide, style 3 - fid, stigma aciculate. Capsule ovoid, c. 1 mm long, containing 2 or 3 seeds, orbicular, 0.5 – 0.6 mm in diam., testa maroon, shiny and distinctly tuberculate, cells bearing whitish asymmetrical protuberances.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB9FFFA2B855CA950CEB3B2.taxon	distribution	Distribution — Stellaria spinulosa occurs in a variety of highland ecosystems across Peru and is considered as the most collected species of the clade (as observed in the material from the different herbaria visited) and extends to Ecuador. Jørgensen & León-Yánez (1999) mentioned the occurrence of the species in Ecuador, which can be confirmed based on an analysis of material stored at MO according to Tropicos. org (2023) and as evaluated by the first author during two visits to MO in 2013 and 2016 and more recently, at PRC, four collections were identified to be S. spinulosa located mostly in central Ecuador, between Chimborazo and Cuicocha. The altitudinal range is from 2800 – 5000 m according to the specimens evaluated.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB9FFFA2B855CA950CEB3B2.taxon	etymology	Etymology — The epithet refers to the spine-like leaves of the plant, which can be felt as tingling by simple touch; spinulosa is derived from the Latin spinula (small spine) in relation to the thorny and pungent characters of the leaves. The former epithet aphanantha is derived from the Greek aphanes (invisible obscure) and anthos (flower), probably referring to the resemblance of the flower sepals to the leaves.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB9FFFA2B855CA950CEB3B2.taxon	discussion	Notes — The specimen C. Gay 1818 (P 00335797) is selected as the lectotype for being most representative with a complete set of morphological characters. As evidenced by this specimen, the species is easily distinguishable from the other members of the clade by the intense yellowish colour of the stems and leaves, the stiff ovate leaf lamina and the nearly sessile flowers with long calyx, the presence of staminoid petals reduced to filaments and the tubercle seeds, which is characteristic for this kind of habit.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB8FFFB2BAF5AE953DFB2B2.taxon	materials_examined	– Lectotype (designated here): Peru, Ayacucho department, Mt. Razuhuillca, Prov. Huanta, 4200 m, A. Weberbauer 7489 (F- 562398!).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB8FFFB2BAF5AE953DFB2B2.taxon	description	Morphological description — Perennial herb, caespitose, densely branched, cushions 1 – 4 cm high and 10 – 15 cm in diam.; roots subwoody. Stems numerous, densely covered by stiff foliage; internodes 0.1 – 0.3 mm long, glabrous; leaves alternate, lamina ovate to linear-lanceolate, 3 – 4 mm long and 1 – 1.5 mm wide, thick and glossy, apex acute and base truncate, yellowish in colour and glabrous on both sides, midrib prominent on underside, margins usually folded toward underside, densely covered by a narrow band of trichomes <0.1 mm long. Plants bisexual-hermaphrodite. Flowers perigynous, terminal and axillary, on 1 – 2 mm long glabrous peduncles, oblong, 3 – 3.5 mm long and 0.8 – 1.1 mm wide; calyx cylindrical-turbinate, crateriform, thicker at base, 2.7 – 3.2 mm long and 2.5 – 3.4 mm wide; sepals 5, imbricate, ovate, 2.5 – 3 mm long and 0.5 – 1 mm wide, glabrous on surface, green or pale green to yellowish-translucent with age, involute, apex acuminate; petals 5, reduced, white-translucent, ovate, apex obtuse, 2 – 2.4 mm long and 0.3 – 0.4 mm wide; stamens 4, episepalous, anthers orbicular-ovate, yellowish-translucent, 0.3 – 0.4 mm long; ovary ovoid-turbinate, 0.6 – 0.9 mm long and 0.6 – 0.8 mm wide, style 3 - fid, stigma aciculate, pale white. Capsule ovoid, 1.2 – 1.5 mm long and 1.1 – 1.3 mm wide, glabrous, containing 3 – 5 seeds, these ovoid, c. 0.5 mm long, testa brown, tuberculate.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB8FFFB2BAF5AE953DFB2B2.taxon	distribution	Distribution — Peru, Ayacucho department at an altitude of c. 4200 m in open grasslands in Puna ecosystems characteristic of the central Andes. No further collections were found, so this is to be considered as a rare species.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB8FFFB2BAF5AE953DFB2B2.taxon	discussion	Notes — The collection A. Weberbauer 7489 shows the typical characters of Stellaria sect. Plettkea by sharing the leaf size, texture, and form, as well as the flower and seeds characteristics as described in the morphological description. Because Macbride (1937) did not mention a specific type specimen in the protologue, a lectotypification is made here, using the locality information in the protologue that matches with the Weberbauer specimen that also exhibits the morphological characters described.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB8FFFB2BAF5D29508BB0D2.taxon	materials_examined	– Holotype: Peru, Áncash, Cajatambo, Schwarze Cordillere über Ocros, auf dürftig bewachsenem, steinigem Boden, 4500 – 4800 m, A. Weberbauer 2804 a (B †). – Neotype (designated by Timaná 2017: 8): Peru, Áncash, Yungay Province, Huascarán National Park, Llanganuco sector, Quebrada Demanda, W of Chacraraju base camp, 09 ° 01 ' S, 77 ° 36 ' W, 4750 – 4900 m, 13 Apr 1985, D. N. Smith & V. Cautivo 10287 (MO- 052068!; isoneotype: F!). Morphological description — See Timaná (2005).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB8FFFB2BAF5D29508BB0D2.taxon	distribution	Distribution — Central Peru, Áncash department inside the Huascarán National Park on highland peaks at altitudes of 4500 – 4900 m, where considered a narrow endemism.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB8FFFB2BAF5D29508BB0D2.taxon	discussion	Notes — Stellaria tetrasticha was originally described as a member of the genus Plettkea by Mattfeld (1934) and later accepted by Bittrich (1993). The species has a mat form with spreading stems, ovate leaves c. 2 mm long bearing carinate acute apex and sepals with ovate-oblong form. Later, Timaná (2017) named Pycnophyllopsis tetrasticha (Mattf.) Timaná based on the morphological affinities found within flower measurements in the neotype he selected. Sharples & Tripp (2019) included a sample of the species in their phylogenetic analysis showing it to be strongly supported as a member of the Plettkea clade.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB8FFF528225E8952EBB552.taxon	materials_examined	Holotype: Peru, Amazonas, Chachapoyas, Leymebamba, Tajopampa Camino Inca, 3696 m, 14 Aug 2016, D. Montesinos 4979 (HUT [HUT- 60181!]; isotypes: B [B 10 0766222!], O [O- 227246!], USM!).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB8FFF528225E8952EBB552.taxon	diagnosis	Diagnosis — The species can be easily distinguished from the other members of the clade by the stiff linear-lanceolate leaves and the prominent calyx apex that forms a needle-like stiff point, a feature that is not seen in any other species.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB8FFF528225E8952EBB552.taxon	description	Morphological description — Perennial herb, forming mats 2 – 4 cm high and 10 – 30 cm in diam.; roots fibrous. Stems suberect or decumbent to prostrate, trailing, densely ramified at base, clothed with older leaves down to base; internodes 2 – 4 mm long, nodes slightly thickened, glabrous, yellowish. Leaves opposite, narrowly involute or plane, eventually curved with age, lamina linear-lanceolate, stiff and coriaceous, truncate at base and aristulate-acuminate near apex, 4 – 6 mm long and <1 mm wide, glabrous on both sides, midrib prominent on underside, margins glabrous toward apex, basally with 0.1 – 0.3 mm long trichomes. Plants bisexual-hermaphrodite. Flowers perigynous, terminal and axillary, always suspended on 2 – 5 mm long, erect and glabrous peduncles; calyx cylindrical, 4 – 6 mm long and 0.8 – 1.1 mm wide; sepals 5, ovate-lanceolate, 4 – 6 mm long and c. 1 mm wide, involute, glabrous on both sides except at base of margins, where minute c. 0.1 mm long trichomes are present, truncate at base and cuspidate at apex, midrib excurrent as a thin 0.1 – 0.25 mm long needle, surface greenish-white turning yellowish with age; petals 5, deeply bifid, bright white, ovate-elliptical, in total 7 – 10 mm long, lobules ovate-lanceolate 0.3 – 0.6 mm long and 0.3 – 0.5 mm wide; filaments c. 0.4 mm long, stamens 5 – 10, episepalous, c. 0.4 mm long, anthers 0.1 – 0.2 mm long, styles 3 - fid, ovary ovoid, 0.2 – 0.3 mm long and c. 0.3 mm wide. Capsule ovoid or nearly so, 0.6 – 0.8 mm long and c. 0.5 mm wide, containing 3 seeds, these roundish or nearly so, flattened, 0.4 – 0.5 mm in diam., testa dark maroon to blackish, covered with rectangular stellate tubercules.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB8FFF528225E8952EBB552.taxon	etymology	Etymology — The specific epithet refers to the Utcubamba river in N Peru that divides Amazonas department from south to north. The new species was found in its uppermost tributaries, and it is very likely that there are further populations on the mountains draining into this river.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB8FFF528225E8952EBB552.taxon	discussion	Notes — This species is known so far from only one collection, but further populations might be encountered after searching in the field. Stellaria utcubambensis differs from S. apurimacensis by having leaves stiff, linear-lanceolate and with margins glabrous toward apex (vs. weak, elliptical-lanceolate and with margins sparsely pilose in S. apurimacensis). Moreover, the internodes in S. utcubambensis are 2 – 4 mm long (vs. 4 – 10 mm long in S. apurimacensis) and the calyx is cylindrical (vs. campanulate in S. apurimacensis).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB6FFF52BAF5B0951C6B2D2.taxon	materials_examined	– Lectotype (designated by Timaná 2023: 502): Chile, Las Mollacas, Cordillera de Illapel, Jan 1888, R. Philippi s. n. (SGO 000001980 [image!]).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB6FFF52BAF5B0951C6B2D2.taxon	description	Morphological description — See Timaná (2005).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB6FFF52BAF5B0951C6B2D2.taxon	distribution	Distribution — Mountain plateaus in Coquimbo, Chile, at altitudes of 2600 – 2800 m, endemic.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB6FFF52BAF5B0951C6B2D2.taxon	etymology	Etymology — The species name is chosen to honour Rodrigo A. Villaseñor Castro (1947 –, Concepción, Chile), a professor in Biology and Natural Sciences, who extensively contributed to the knowledge of the Chilean flora.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB6FFF52BAF5B0951C6B2D2.taxon	discussion	Notes — The species conspicuously deviates from the other members of the Plettkea clade by its dense lanuginose indumentum and by its shrubby habit. Timaná (2005) proposed to classify this species in its own new subgenus, Pycnophyllopsis subg. “ Coquimbo ”, but this name, because it appeared in a thesis, was not effectively (and therefore not validly) published according to Art. 30.9 of the Code (Turland & al. 2018). The same applies to the species combination under Pycnophyllopsis and the lectotypification, all of which were not included in Timaná’s (2017) paper on the genus. Flower and seed morphology provide evidence for a position in the Plettkea clade. In his thesis, Timaná (2005) depicted a representative of this species in an ITS tree in a lineage with Pycnophyllopsis cryptantha and P. weberbaueri, thus supporting this position. However, these phylogenetic results cannot be reproduced because the sequences are not available and the tree was never properly published. There are two specimens at SGO (old herbarium number 048875 corresponding to barcode SGO 000001980 and old herbarium number 090982 corresponding to barcode SGO 000001981) that were apparently collected by Philippi from the same locality, but the latter lacks a date.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB6FFF52BAF5C8950CFB7B2.taxon	materials_examined	– Lectoype (designated here): Peru, Vincocaya, statio viae ferreae ad Arequipam, 4100 m, 24 Aug 1902, A. Weberbauer 1373 (MOL [MOL 00000507!]). – Fig. 1 G.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB6FFF52BAF5C8950CFB7B2.taxon	description	Morphological description — See Timaná (2005).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB6FFF52BAF5C8950CFB7B2.taxon	distribution	Distribution — The species inhabits highland plateaus, also known as subnival puna, at altitudes of 4660 – 5000 m. It is known to occur in the Arequipa and Moquegua departments of Peru, while its occurrence in the Bolivian Andes is not confirmed.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB6FFF52BAF5C8950CFB7B2.taxon	discussion	Notes — The species was first described as Pycnophyllum weberbaueri Muschl. by Muschler (1911), presumably based on the cushion growth form, plicate leaves and apical flowers. Later, the species was transferred to the genus Pycnophyllopsis by Timaná (2017), as Pycnophyllopsis weberbaueri (Muschl.) Timaná, based on the consistently pentamerous flowers with three free styles. Muschler (1911) apparently described characters for Stellaria weberbaueri such as true petals, which are actually not present in the specimens examined. Moreover, S. weberbaueri has leaves that do not overlap to be completely imbricate, giving the general impression of a loose cushion with longer internode length. Sharples & al. (2021) reported “ Stellaria weberbaueri (Muschl.) M. T. Sharples & E. A. Tripp ” in their Appendix 2, but this name has not been validly published anywhere.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB6FFF628225E2950F1B3B2.taxon	materials_examined	Holotype: Peru, Amazonas, Chachapoyas, Leymebamba, construcciones de piedra, restos arqueológicos La Boveda, 3540 m, 20 Jun 2018, D. Montesinos 6970 a (HSP [HSP- 20000!]; isotype: B [B 10 1098616!]).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB6FFF628225E2950F1B3B2.taxon	diagnosis	Diagnosis — This species is similar to Stellaria laevis, from which it can easily be distinguished by its leaf margin, which is ciliate in the lower-middle part of the leaf, whereas in S. laevis the margin is completely covered by thin trichomes.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB6FFF628225E2950F1B3B2.taxon	description	Morphological description — Perennial herb, forming dense mats, 6 – 10 cm high and up to 20 cm in diam.; root woody. Stems decumbent or more commonly curved, 10 – 18 cm long, branched; internodes 1 – 5 mm long, glabrous, sometimes bearing a few trichomes at node base, nodes thickened. Leaves involute, opposite, basally fused, lamina ovate-lanceolate to linear-lanceolate, subtruncate at base and mucronate at apex, stiff or spine-like, 6 – 8 mm long and 1 – 1.5 mm wide, glabrous, thick, with midrib prominent, densely covered by thin trichomes at base, tending to be glabrous toward apex; trichomes multicellular, straight or curved, 0.2 – 0.5 mm long, increasing in length toward base of lamina; older foliage usually covering stems, yellowish in colour. Plants bisexual-hermaphrodite. Flowers perigynous, terminal and axillary, on erect or slightly curved, 5 – 15 mm long peduncles, bearing tiny protuberances on surface as well as minute trichomes, rarely glabrous, old flowers persistent; calyx cylindrical, imbricate, turbinate, slightly wider at base, 8 – 10 mm long and 1.4 – 2.2 mm wide; sepals 5, lanceolate to narrowly ovate-lanceolate, involute, pale green to dark yellow with age, 5 – 7 mm long and 1.5 – 2 mm wide, midrib prominent, margins entire, truncate at base, acute at apex, surface glabrous or nearly so; petals 5, strongly reduced, 2 – 3 mm long and 1 – 1.8 mm wide, translucent, elliptical, apex obtuse; stamens 5, 1.5 – 2 mm long; style 3 - fid, less than 1 mm high; ovary cylindrical, 0.9 – 1.1 mm long and 0.8 – 1 mm wide, stigma aciculate and obtuse. Capsule ovoid, 0.8 – 1 mm long, glabrous, containing 4 – 6 seeds, these ovate, compressed, c. 1 mm in diam., testa maroon, densely tuberculate.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB6FFF628225E2950F1B3B2.taxon	etymology	Etymology — The specific epithet derives from the Greek words xanthos, yellow, and phylla, leaves, referring to the persistent, yellow leaves along the stems of the plant.	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
03C987A5FFB6FFF628225E2950F1B3B2.taxon	discussion	Notes — Stellaria xanthophylla shows morphological similarities with S. engleriana but can be differentiated by the following characters: bearing thin trichomes at the base of the lamina (vs. dense trichomes at the base in S. engleriana); sepal form, size and texture (lanceolate to narrowly ovate-lanceolate, 5 – 7 mm long and 1.5 – 2 mm wide, surface and margins glabrous or nearly so in S xanthophylla vs. ovate-oblong, 3 – 4 mm long and 1 – 1.5 mm wide, with a ciliate lamina surface and margin in S. engleriana).	en	Montesinos-Tubée, Daniel B., Borsch, Thomas (2023): Molecular phylogenetics and morphology reveal the Plettkea lineage including several members of Arenaria and Pycnophyllopsis to be a clade of 21 South American species nested within Stellaria (Caryophyllaceae, Alsineae). Willdenowia 53 (3): 115-148, DOI: 10.3372/wi.53.53301, URL: https://doi.org/10.3372/wi.53.53301
