Calamagrostis crispifolius Sylvester, 2019

Sylvester, Steven P., Soreng, Robert J., Bravo-Pedraza, William J., Cuta-Alarcon, Lia E., Giraldo-Canas, Diego, Aguilar-Cano, Jose & Peterson, Paul M., 2019, Paramo Calamagrostis s. l. (Poaceae): An updated list and key to the species known or likely to occur in paramos of NW South America and southern Central America including two new species, one new variety and five new records for Colombia, PhytoKeys 122, pp. 29-78 : 29

Calamagrostis crispifolius Sylvester sp. nov. Fig. 1

Type.

COLOMBIA. Magdalena: flanco occidental de la Sierra Nevada de Santa Marta, páramo, abundantisima, cubre gran parte del páramo, 3140 m alt., 29 Jan. 1959, R. Romero Castañeda 7141 (holotype: COL (COL000172001!); isotype: US (US01246667!)).

Diagnosis.

Differs from all other species of Calamagrostis s.l. by a combination of strongly curled, readily deciduous leaf blades in mature plants that form a basal mat to 20 cm tall, open inflorescences with generally patent branches, spikelets (3.5 –)4– 5.5 mm long, with sessile florets and a rachilla prolongation (not including hairs) reaching from 2/3 to almost the apex of the lemma, with short hairs <1 mm long and an awn inserted just above the middle of the lemma, 5-7.2 mm long, anthers 1.5-2.7 mm long.

Description.

Plants perennial, tufted, forming short dense tufts, mats to 40 cm wide, with short vertical or oblique rhizomes. Bases covered with fibrous old basal sheaths, with fallen curled leaf blades often forming large masses on the ground between tufts. Tillers intravaginal. Culms 48-64 cm tall, 1.5-2.2 mm wide, striate, erect, greatly exerted from the basal foliage, nodes and internodes terete, smooth but becoming scabrous below the nodes and towards the inflorescence, with dense scabrocities just below the inflorescence; (0-)1 node exposed at flowering; uppermost internodes 38-42 cm long. Sheaths striate, moderately keeled; flag leaf sheaths 20-25 cm long; upper culm sheaths glabrous and smooth with minute papillae present on the adaxial surface; basal leaf sheaths 4-12 cm long, shorter than the internodes, glabrous and lightly scabrous. Ligules not stipulate; upper culm ligules 2.5-10 mm long, acute with a rounded or bidentate apex, scarious to coriaceous, 2-veined but without notable lateral keels, apices denticulate, fimbriate or short ciliate, ligule abaxial surface lightly to densely scabrous with short scabers; ligules of innovations 2.2-10 mm long, strongly decurrent with the sheaths, truncate to acute, scarious to coriaceous when shorter, lightly to densely scabrous on the abaxial surface. Leaf blades 5 –15(– 30) cm long, 0.5-1.5 mm wide, cylindrical in outline, when rolled the blades form a basal mat to 20 cm tall and much shorter than the exerted culms, strongly curled in mature plants [or when dry?], appearing readily deciduous and snapping off when the plant reaches maturity leaving an abscission zone and the ligule exposed, sometimes recurved to straight in immature plants [or when moist?], conduplicate to convolute, rigid, glabrous, abaxially finely scabrous, adaxially densely scabrous, edges smooth or slightly scaberulous, apex pungent; flag leaf blade ca. 2.9 cm long, recurved, slightly narrower than the basal blades. Panicles (5.5 –)9– 20 cm long, 3-10 cm wide, open, rarely contracted in young specimens, exerted or rarely subincluded in the flag leaf, open and diffuse, oval, greenish-purple or golden-purple; main panicle axis terete, glabrous, lightly to moderately scabrous, spikelets found diffusely on the proximal half of the primary branches, lower internodes 2-4 cm long; panicle branches spreading to slightly ascending, rarely contracted; primary panicle branches 2-6 cm long, bearing 1-10 spikelets per branch, verticillate in clusters of 2-5, terete, glabrous, almost smooth to scabrous; pedicels (3 –)6– 22 mm long, usually much longer than the spikelets, glabrous, lightly to moderately scabrous. Spikelets 1-flowered, not strongly laterally compressed, disarticulating above the glumes; glumes, lemma and palea not noticeably asymmetrical. Glumes (3.5 –)4– 5.5 mm long, subequal, the lower glume ca. 0.3 mm shorter than the upper glume, narrowly lanceolate, membranous, purplish, lustrous, dorsal surface smooth or scaberulous distally, keels lightly scabrous distally or scabrous throughout, apices acute, finely denticulate, erose; lower glume 1-veined; upper glume 3-veined, lateral veins reaching from ¼ to past half the length of the glume, 1 or 2 cross veins between the keel and lateral vein infrequently present in ca. 10% of spikelets seen (requires 50 × magnification). Floret sessile, almost reaching the apex of the glumes, sometimes passing the apex of the lower glume. Lowermost rachilla internode not prolonged between the glumes and the floret. Lemmas 3.7-4.6 mm long, 5-veined, veins not evident; the same consistency as the glumes, golden, glabrous, scaberulous throughout or lustrous and faintly to densely muriculate with the apex sometimes becoming scaberulous, apex shortly emarginate with lobes finely denticulate, awns 5-7.2 mm long, amply passing the glumes, twisted at the base, slightly curved, densely scabrous throughout, inserted just above the middle of the lemma, at 2.2-2.5 mm from the lemma base. Paleas 0.3-0.8 mm shorter than the lemma, of the same consistency and colour, keels smooth and notable, apex bidentate. Callus rounded, short, articulation oblique, with a basal tuft of short hairs 0.2 –0.7(– 0.8) mm long. Rachilla (2 –)3– 3.5 mm long, reaching from 2/3 to almost the apex of the lemma, with copious short hairs 0.5-1 mm long, the hairs reaching from 4/5 to almost the apex of the lemma and usually surpassing the palea. Lodicules 2, 0.4-0.6 mm long, membranous, 2-lobed, acute to slightly acuminate. Stamens 3, anthers 1.5-2.7 mm long. Ovary ca. 0.5 mm long, small, styles 2, stigmas plumose with secondary branching, short. Caryopsis ca. 1.8 mm long, ca. 0.7 mm wide, elliptic, rounded triangular in transection, hilum narrowly elliptic, ventral groove shallow and not conspicuous, pale brown, embryo ca. 0.3 mm long, apex with remains of styles and stigmas; endosperm firm.

Distribution and ecology.

Colombia, Venezuela. Known from páramos of the Sierra Nevada de Santa Marta, northern Colombia and the Sierra de Perija, Venezuela. For the Sierra Nevada de Santa Marta, specimens are known from páramo vegetation on both the western and eastern flanks of the massif. For the Sierra de Perija, specimens are known from both the northern and southern extents of the mountain range. It is found growing between 2700-3570 m in páramos with dry soils that are often subject to fires. The plant forms dense cushion-like mats or clumps and it is a dominant component of certain páramos. The type specimen label includes "Abundantisima, cubre gran parte del páramo”, i.e. highly abundant and covers a large part of the páramo. The specimen label of Barclay and Juajibuoy 6545 (US) also states "the dominant grass on these slopes, extending up to the top of ridge", thus implying that it is a dominant component of the páramos of the Sierra Nevada de Santa Marta.

The degree of curling of leaf blades in the different specimens studied may relate to the level of maturity of the plant or also the local microclimate, with the specimen label of Barclay and Juajibuoy 6545 (US) stating "leaves very fine and rolled, when dry they curl". The characteristic of readily deciduous leaf blades is also interesting, with the specimen label of Barclay and Juajibuoy 6545 (US) also mentioning that "large masses of these [the fallen curled blades] on the ground between clumps [of the plant]".

Other specimens examined.

COLOMBIA. Magdalena: Sierra Nevada de Santa Marta, Laguna Chubdula, 3480 m alt., 10°55'N; 73°53'W, 29 Dec. 1972, Kirkbridge & Forero 1775 (MO); Sierra Nevada de Santa Marta, alrededores de cabeceras del Río Sevilla, 3050-3300 m alt. [US specimen label states 'The dominant grass on these slopes, extending up to the top of ridge. West and north facing slopes, on south side of river above campsite, sta.1,6., alt. 3320-3570 m’], 20 Jan. 1959, H.G. Barclay & P. Juajibioy 6545 (MO, US-3652630); Sierra de Perija, east of Manuare, Sabana Rubia, páramo, 3000-3100 m alt., 6 Nov. 1959, J. Cuatrecasas & R. Romero Castañeda 25021 (US [3 sheets]).

VENEZUELA. Zulia: Maracaibo Distr., Sierra de Perija, Serranía de Valledupar, Campamento Monte Viruela, on tepuí-like limestone massif 5 × 2.5 km in size, on the international boundary, 10°25.2167'N; 72°52.7'W, 3100 m alt., 25-28 Dec. 1974, S.S. Tillett 747-882 (MO); Perijá Distr., Sierra de Perija, Serranía de los Motilones, mesa below international boundary on main ridge, headwaters of Río Negro, Campamento Frontera II, 10°0.2167'N; 72°58.4167'W, 3000 m alt., 27 Nov.-5 Dec. 1974, S.S. Tillett & K.W. Hönig 746-618 (MO); Serranía de Valledupar, international boundary, headwaters of Río Guasare, 10°23.13'N; 72°52.0833'W, 2700-3300 m alt., 10-19 Dec. 1974, S.S. Tillett 747-1072 (MO).

Preliminary conservation status.

Vulnerable (VU). Despite the species being known from seven collections spanning two Cordilleras, the páramos of Colombia are currently facing threats principally from mining ( Pérez-Escobar et al. 2018) and an uncertain future. Our preliminary conservation status of VU is deemed adequate until further research is done.

Etymology.

The species epithet refers to the strongly curled leaf blades which make it distinct from all other páramo taxa of Calamagrostis s.l. with open panicles.

Notes.

To our knowledge, there are no species of Calamagrostis s.l. with readily deciduous leaf blades that snap off when the plant reaches maturity leaving an abscission zone and the ligule exposed and covering the ground surrounding the plant tufts. This, coupled with the strongly curled nature of the leaf blades, makes this species unique. The character of curled leaf blades is very uncommon in the genus Calamagrostis , with the closest resembling species with this character being Calamagrostis crispa ( Rúgolo & Villav.) Soreng, a species found in dry Andean grassland of Bolivia, Chile, Peru and Northeast Argentina ( Rúgolo de Agrasar 2012: 193). The blades of mature plants of C. crispa are generally curved rather than strongly curled, as in C. crispifolius . Calamagrostis crispa also differs from C. crispifolius by the short, few-flowered, inflorescences that are included within the basal foliage, large spikelets with glumes 5-8 mm long and lemmas (4.4 –)5– 5.5 mm long, amongst other characters.

Calamagrostis crispifolius also shares certain similarities with C. effusa in terms of characters of the inflorescence i.e. the open panicles with verticillate panicle branches, the short glumes to 5.5 mm long, the awn being inserted in the upper half of the lemma and, most importantly, the long rachilla usually extending past the apex of the palea and bearing short hairs <1 mm long. Calamagrostis crispifolius and C. effusa also share a peculiar character of cross veins between the lateral veins and keel of the upper glume, but these are only noticeable at 50 × magnification in about 1 in 10 spikelets. A more exhaustive search for this character in other taxa within Calamagrostis s.l. should be done to check its exclusiveness to C. crispifolius and C. effusa . Calamagrostis crispifolius can be easily distinguished from C. effusa by the strongly curled leaf blades with pungent apices which form a basal mat to 20 cm high that is usually much shorter than the flowering culms, while C. effusa has stiffly erect blades with obtuse apices forming tussocks 40 –60(– 107) cm tall. Ligule characteristics also differ, with C. crispifolius having ligules 2.2-10 mm long with acute apices, while C. effusa has ligules 1-2 mm long with truncate apices. In a recent molecular analysis, Calamagrostis effusa was found to be sister to Chascolytrum Desv. ( Saarela et al. 2017), possibly warranting its own generic placement. Further collecting of this new species, with a focus on molecular sampling, should be done to clarify its phylogenetic affinities.

Specimens of C. crispifolius from the Sierra Nevada de Santa Marta, Colombia, differ from Venezuelan specimens in a number of attributes and may represent a subspecies, although further collections and studies need to be made to confirm this. Colombian specimens have narrower leaf blades (0.5-0.75 mm wide), shorter ligules (2.2-4 mm long), usually longer anthers (to 2.7 mm long) and rachillas with short hairs that often reach the apex of the lemma. Venezuelan specimens have broader leaf blades (to 1.5 mm wide), longer ligules (4-10 mm long), shorter anthers (1.5-2 mm long) and rachillas with short hairs that usually do not reach the apex of the lemma.

Figures

Figure 1. Calamagrostis crispifolius; A lower portion of plant, showing basal tuft of curled leaves B ligular area C upper portion of plant showing inflorescence and flag leaf blade D primary branch of the inflorescence E lower glume, dorsal view F upper glume, dorsal view G spikelet, with floret already fallen, lateral view H spikelet, with floret, lateral view I lemma, dorsal view J lemma, lateral view K stylar branch and stigma L palea ventral view, showing the ovary, stamens and lodicules M ovary and lodicules, ventral view N immature caryopsis, dorsal view showing embryo; drawn by Alice R. Tangerini from the isotype, R. Romero Castaneda 7141 (US).