Lachemilla argentea D.F.Morales-B. & Romol., 2019

Morales-Briones, Diego F., Romoleroux, Katya & Tank, David C., 2019, Three new species of Lachemilla (Rosaceae) from South America, PhytoKeys 127, pp. 93-119 : 93

publication ID	https://dx.doi.org/10.3897/phytokeys.127.36324
persistent identifier	https://treatment.plazi.org/id/86BC66CD-6672-C2F3-93FC-CC07021A87B9
treatment provided by	PhytoKeys by Pensoft
scientific name	Lachemilla argentea D.F.Morales-B. & Romol.
status	sp. nov.

Treatment

Lachemilla argentea D.F.Morales-B. & Romol. LSID sp. nov. Figs 7 View Figure 7 , 8 View Figure 8 , 9 View Figure 9

Diagnosis.

Lachemilla argentea differs from L. holmgrenii Rothm. and L. adscendens (Rothm.) Rothm. by its herbacecous habit with decumbent branches, conspicuous basal reniform tripartite leaves with an adaxial silvery villous pubescence, and a turbinate to urceolate hypanthium with pilose-sericeous pubescence.

Type.

COLOMBIA. Bogotá, Distrito Capital: Páramo de Cruz Verde. Path to Laguna El Verjón, 4.56102N, 74.02172W, alt. 3495 m, 26 September 2013, Morales-Briones D.F. & Uribe-Convers S. 523 (holotype: ID!, isotypes: ANDES!, QCA!).

Description.

Decumbent herbs; branches decumbent up to 12 cm long, sericeous-villous. Basal stipules 5-10 mm long, adnate to the petiole, sparsely villous, membranous, brown at base, free at apex. Basal leaves tri-parted, blade reniform in outline, 6-7 (-10) × 7.5-10 (-1.3) mm, 3 lobes, chartaceous, slightly plicate, lobes unequally obovate-rhomboid, margin dentate-incised, teeth 3-6 on each of the lobes, lower surface sparsely sericeous-villous, upper surface villous; basal petiole 5-12 mm long. Distal stipules and distal leaves reduced adnate and connate, forming verticillate lobed sheaths; sheath lobes 6-10 ascending or slightly spreading; lobes 4-7 × 1.5-3 mm, lanceolate, entire or trilobed, decreasing in size. Inflorescences axilar or terminal glomerulate cymes, flowers aggregate at the distal part. Floral bracts 2-4 mm long, free, incised, and ascending; 3-7 flowers per inflorescence; pedicels 0.5-1 mm long, slightly pilose. Flowers 2-2.5 mm long; hypanthium turbinate to urceolate, green or reddish, pilose-sericeous outside, glabrous within; 4 episepals and 4 sepals green or slightly reddish, straight, abaxially pilose-sericeous, adaxially glabrous; episepals triangular, 0.7-0.8 × 0.4-0. 5 mm, apex acute; sepals triangular-ovate, 0.75-0.85 × 0.5-0.6 mm, apex acute; stamens 2 adnate to the floral disc; carpels 2-3, stigma clavate. Two achenes, ca. 1-1.5 × 0.6-0.8 mm, globose-ovoid.

Additional specimens examined.

COLOMBIA. Bogotá, Distrito Capital: Páramo de Cruz Verde, Bogotá-Choachí road, km 11.2, alt. 3257 m, 1 May 1972, Cleef A. 3330A (COL). Bogotá, Distrito Capital: Páramo de Cruz Verde, path to Laguna El Verjón, 4.56102N, 74.02172W, alt. 3495 m, 26 September 2013, Morales-Briones D.F. & Uribe-Convers S. 522 (ANDES, ID, QCA). Boyacá: Güicán, Sierra Nevada del Cocuy, road to the small house, in ‘Lagunilla’ area, towards to Púlpito del Diablo, 6.37906N, 72.33995W, alt. 3950 m, 18 September 2013, Morales-Briones D.F. et al. 476 (ANDES, ID, QCA). Boyacá: Duitama, road to Páramo de la Rusia, 22 km from Duitama, before ‘fábrica de arepas Buenos Aires’, 5.92656N, 73.08826W, alt. 3650 m, 24 September 2013, Morales-Briones D.F. & Uribe-Convers S. 507 (ANDES, ID, QCA). Boyacá: Belén, Vereda de San José, Páramo del Consuelo, 18 km from Belén, on the way to Encino, 6.02920N, 72.96523W, alt. 3768 m, 23 September 2013, Morales-Briones D.F. & Uribe-Convers S. 499 (ANDES, ID, QCA). Boyacá: Páramo de Pisba, Socha-La Punta road, km 72, near to M.O.P campsite. El Cadillal, stony slope, alt. 3500 m, 8 June 1972, Cleef A. 4235 (COL). Boyacá: Páramo NW of Belén, Vereda S. José de la Montaña, Alto de las Cruces and surroundings, alt. 3790 m, 24 February 1972, Cleef A. 1756 (COL). Boyacá: Páramo de Pisva, Socha-La Punta road, km 61, 5.6 km east of Los Pinos, Alto de Granados, alt. 3635 m, 12 June 1972, Cleef A. 445813 (COL). Boyacá: Páramo de Pisva, flank SW of Morros de S. Gabriel, 2 km SW of Laguna Batanera, alt. 3670 m, 18 June 1972, Cleef A. 4702A (COL). Cundinamarca: Villa Pinzón, Páramo de Guachenque. Entrance to the Laguna del Valle and surroundings of Laguna del Mapa, 5.21641N, 73.52675W, alt. 3346 m, 25 September 2013, Morales-Briones D.F. & Uribe-Convers S. 514 (ANDES, ID, QCA). Cundinamarca: Páramo de Palacio, 18 km from the road, alt. 3485 m, 16 December 1971, Cleef A. 327 (COL). Santander: Vetas, road to the Laguna Pajaritos, at the entrance of private property, 7.33349N, 72.85373W, alt. 3539 m, 14 September 2013, Morales-Briones D.F. et al. 437 (ANDES, ID, QCA). Santander: Vetas, road to Laguna Pajaritos, 7.33086N, 72.85106W, alt. 3585 m, 14 September 2013 Morales-Briones et al. D.F. 440 (ANDES, ID, QCA). Santander: Páramo de Almorzadero, road Presidente-Cerrito, km 98, 6.99470N, 72.68187W, alt. 3567 m, 16 September 2013, Morales-Briones D.F. et al. 458 (ANDES, ID, QCA). Santander: Páramo de Almorzadero, road Presidente-Cerrito, km 98, 6.96333N, 72.68488W, alt. 3801 m, 16 September 2013, Morales-Briones D.F. & Uribe-Convers S. 459 (ANDES, ID, QCA).

Mixed specimens examined.

the following specimens are collections with two different species under the same number, one (a) correspond to L. argentea . Boyacá: Páramo de Pisva, Alto de Granados, 5 km E of Los Pinos, alt. 3735m, 15 June 1972, Cleef A. 4593A (a) (COL). Boyacá: Güicán Sierra Nevada del Cocuy, after Cabañas Kanwara, 17.7 km from 'water plant’, Lomas Las Pajas, 6.47093N, 72.35934W, alt. 4105 m, 17 September 2013, Morales-Briones D.F. & Uribe-Convers S. 473 (a) (ANDES, ID, QCA). Santander: Páramo de Santurbán, Berlín, 7 km from Vetas, 7.24935N, 72.89784W, alt. 3567 m, 13 September 2013, Morales-Briones D.F. et al. 431 (a) (ANDES, ID, QCA).

Deviating specimens examined.

The following specimens have similar habit, leaf shape, and pubescence to L. argentea , but they only differ in having glabrous flowers. These specimens may represent only a variety of L. argentea , but they are maintained here as uncertain taxa until more material is available or can be included in phylogenetic analyses. Boyacá: Páramo NW of Belén, Quebrada Minas. Hoya CLLA, Slopes N of Valle Lajas, alt. 3835m, 2 March 1973, Cleef A. 2119A (COL). Boyacá: Páramo de Pisva, Road Socha-La Punta, km 61.5, 6 km E from Los Pinos Alto de Granados, alt. 3630 m, 14 June 1972, Cleef A. 4545 (COL). Cundinamarca: Páramo de Palacio aprox. 1 km E from 'la mina de cal’, alt. 3853 m, 19 May 1972, Cleef A. 3853A (COL). Quidio/Tolima: Paramillo of Quindio and Páramo de Tolima. 13 km from Valle de Cocora. 4.64433N, 75.43060W, alt. 3645 m, 4 October 2013, Morales-Briones D.F. et al. 543 (ANDES, ID, QCA). Santander: Vetas, road to Laguna Pajaritos, 7.33086N, 72.85106W, alt. 3585 m, 14 September 2013, Morales-Briones D.F. et al. 439 (ANDES, ID, QCA).

Distribution and ecology.

Lachemilla argentea is distributed in the central northern (primarily) regions of the Cordillera Oriental between 3275 and 3735 m ( Fig. 6 View Figure 6 ). This species occurs in humid and very humid páramos dominated by grasses, shrubs, and dwarf shrubs. Lachemilla argentea can be found living in sympatry with multiple species of Lachemilla , including L. aphanoides , L. hispidula , L. nivalis , L. mandoniana (Wedd.) Rothm., L. purdiei , and L. vulcanica (Schltdl. & Cham.) Rydb. Flowering and fruiting collections dated from the months of February, May, June, and September.

Etymology.

The specific epithet refers to the silvery aspect of the basal leaves.

Conservation status.

Lachemilla argentea is a common element throughout its distributional range, and occurs in several well-conserved areas. Following the IUCN (2017) guidelines, we consider this species is not at risk and should be categorized as least concern (LC). Nonetheless, the rapid deterioration and conversion to agriculture of proximate areas where L. argentea occurs may put this species at some threat in the near future.

Notes.

Lachemilla argentea resembles L. holmgrenii and L. adscendens by having basal tripartite leaves and stem leaves fused to the stipules forming verticillate sheaths with one tripartite lobe that is larger than the remaining lobes, but differs in having an herbaceous habit with decumbent branches, while the other two species are subshrubs with suberect to ascending branches. Furthermore, L. argentea has conspicuous basal reniform tripartite leaves with an adaxial silvery villous pubescence, while L. holmgrenii and L. adscendens have smaller hirsute leaves. These species also vary in the number of sheath lobes; L. argentea has 6-10 ascending or slightly spreading lobes, while L. holmgrenii and L. adscendens have 5-7 loosely ascending to reflexed lobes, and eight erecto-patent lobes, respectively. By having conspicuous basal leaves, L. argentea also resembles L. sprucei , but the latter is a subshrub with suberect stems and coriaceous 5-parted basal leaves, in addition to distinct 3-parted distal leaves.