Deschampsia podophora (Pilg.) Saarela var. mutica 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

Deschampsia podophora (Pilg.) Saarela var. mutica Sylvester var. nov. Fig. 3

Type.

COLOMBIA. Cundinamarca: Mun. Santa Rosa-Usme, Sumapaz páramo, by Laguna Larga, in swamp at the edge of the lake in open páramo country, 3700 m alt., 19 Aug. 1985, J.R.I. Wood 5033 (holotype: FMB (FMB11918!); isotypes: COL (COL000434793!), K [2 sheets]!).

Diagnosis.

Deschampsia podophora var. mutica differs from D. podophora by the lemmas being muticous and lacking awns (vs. lemmas usually with a well-developed dorsal awn inserted in the lower or middle third of the spikelet, measuring 1.5 –3.5(– 4) mm long and usually not surpassing the glumes), tussock-forming habit with multiple culms and leaves mainly cauline, without a basal mat clearly shorter than the flowering culms (vs. plants forming short isolated tufts with solitary culms and the leaves forming a short basal mat clearly shorter than the largely exerted flowering culms), inflorescences often sub-included in the sheaths and blades (vs. flowering culms largely exerted from basal mats); leaf blades 11-22 cm long, 0.35-0.6 mm wide when rolled, often dimorphic, those of the innovations filiform and cylindrical to subelliptic in outline, while upper flowering culm blades 6.5-25 cm long, 2-7 mm wide when opened out, usually wider and flat, conduplicate or convolute towards the pungent apices (vs. leaf blades 5-8 cm long, 2-3 mm wide, not clearly dimorphic, with all blades flat or conduplicate, apices obtuse), ligules 4-11 mm long (vs. ligules generally longer, 10-22 mm long), anthers (1.4 –)1.8– 1.9 mm long (vs. anthers (0.7 –)1.2– 1.5 mm long), upper glume lateral veins reaching from ½ to 2/3 the length of the glume (vs. upper glume lateral veins short, < ½ length of glume).

Description.

Tufted perennial with vertical rhizomes forming medium-sized tussocks with leaf blades both basal and cauline and some cauline blades often surpassing the inflorescence. Culms 26-110 cm tall, to 3 mm wide, erect, striate, nodes and internodes terete, smooth and lustrous; nodes hidden in the sheaths with no nodes exposed at flowering; uppermost internodes 23-32.5 cm long, not, or not pronouncedly, longer than the sheath; Sheaths striate; flag leaf sheaths 22-38 cm long; upper culm sheaths lax, glabrous and smooth; basal leaf sheaths 4.5-20 cm long, glabrous and smooth, longer than the internodes. Ligules not stipulate; upper culm ligules 7.5-11 mm long, strongly decurrent with the sheaths, long acuminate, membranous to slightly coriaceous, without notable lateral keels, apices erose or narrowly bifid, sometimes fimbriate, abaxial surface smooth; ligules of innovations 4-9 mm long, slightly to strongly decurrent with the sheaths, long acuminate, membranous to slightly coriaceous, lateral keels sometimes notable, apices a narrow bifid point, sometimes slightly erose, abaxial surface smooth or sometimes slightly scabrous at the apex. Leaf blades sometimes dimorphic, those of the innovations filiform and cylindrical to subelliptic in outline while those of the upper flowering culm are usually wider and flat, conduplicate, or convolute towards the apices; leaf blades of innovations 11-22 cm long, 0.35-1 mm wide when rolled or folded, narrow and conduplicate or filiform involute or convolute and cylindrical to subelliptical in outline, rarely completely flat, sometimes opening out to become flat at their apices, straight and erect, glabrous, abaxially smooth, adaxially lightly scaberulous along the veins or rarely smooth, edges smooth or slightly scaberulous, apex obtuse to slightly pungent; leaf blades of lower flowering culm to 1.2 mm wide when rolled or folded, similar to those of the innovations or slightly wider; leaf blades of upper flowering culm 6.5-25 cm long, 2-7 mm wide when opened out, flat, conduplicate or convolute towards the apices, glabrous, abaxially smooth to finely scaberulous, sometimes becoming densely scabrous at the apex, adaxially smooth or scaberulous towards the margins, veins pronounced, numerous and tightly packed, edges smooth or slightly scaberulous, apex acute to pungent; flag leaf blade ca. 2.9 cm long, recurved, slightly narrower than the basal blade. Panicles 10-25 cm long, 5-8 cm wide, open and diffuse with main axis having long internodes, oval, usually slightly to moderately included in the uppermost sheath and/or blade, greenish-purple, spikelets tending to be laxly glomerate on the distal half of the inflorescence branches with the proximal half usually lacking spikelets; main panicle axis terete to slightly compressed, usually with a narrow groove running down both sides, glabrous, smooth to lightly scaberulous, internodes tending to be very long, lower internode 5.5-11.5 cm long; panicle branches flexuous, spreading, pendulous or divergent at a 45° angle to slightly ascending; primary panicle branches 1.5-8 cm long, bearing 10 to over 50 spikelets per branch, terete and slightly grooved, verticillate in clusters of 2 or 3, glabrous, almost smooth to lightly scabrous; pedicels 0.5-2.5 mm long, usually shorter than the spikelets, glabrous, lightly scabrous. Glumes 4.5-4.9 mm long, subequal, the lower glume 0.3-0.6 mm shorter than the upper glume, membranous, purplish-green, lustrous, smooth or sometimes lightly scabrous throughout the keel of the upper glume; lower glume 1-veined, apex usually bidentate, less frequently finely denticulate or erose; upper glume 3-veined, lateral veins reaching from ½ to 2/3 the length of the glume, apex usually acuminate, sometimes finely denticulate. Floret stipitate, much shorter than the glumes, never passing the apex of the lower glume. Lemmas 2.8-3.4 mm long, of the same consistency as the glumes, light green with purple tinges towards apex, becoming golden at maturity, glabrous, smooth with the keel apex rarely scaberulous, apex truncate and denticulate, usually with 5 clearly distinguished teeth, 0.3 mm long, and erose between the teeth, 5-veined, veins not evident; muticous and lacking an awn. Rachilla 1.5-2.5 mm long, reaching from 2/3 to 4/5 the length of the lemma, with copious short to medium-sized hairs 0.5-1.4 mm long, the hairs reaching from 4/5 to almost the apex of the lemma and usually surpassing the palea, apex of rachilla often clavate. Stamens 3, anthers (1.4 –)1.8– 1.9 mm long.

Distribution and ecology.

Endemic to Colombia. Known from páramos of the Cordillera Oriental and Cordillera Central of the Colombian Andes. For the Cordillera Oriental, the species is known from Departamento Cundinamarca municipalities Usme and Santa Rosa and Páramo Pisba of Departamento Boyacá. For the Cordillera Central, the species is known from Páramo del Quindio and Páramos de la Laguna del Mosquito of Departamento Caldas. Found in humid, swampy areas, often by rivers or lakes and less often in more mesic habitats, such as road verges (presumed damp). The type specimens were collected from swampy areas bordering the Laguna Larga of the Sumapaz páramo in Cundinamarca. The holotype shows signs of grazing, with blades and culms abruptly cut.

Other specimens examined.

COLOMBIA. Boyacá: Mun. Socota: Páramo Pisba, Peña Negra, lagoon "Choro Negro", páramo with Calamagrostis effusa , Espeletia sp., Chusquea sp., Diplostephium sp. etc., swampy, 3500 m alt., 11 Feb. 1999, D. Stančik & S. Medina 2351 (COL-000184768; FMB-051200); Páramo Pisba, Alto de Calarca, humid grassy páramo with Calamagrostis effusa , Espeletia sp., Chusquea sp. et bunch Grass, 3600 m alt., 11 Feb. 1999, D. Stančik & S. Medina 2331 (FMB-046617). Caldas: Páramo del Quindio, swale in páramo valley, 3700-4200 m alt., 15-20 Aug. 1922, F.W. Pennell & T.E. Hazen 9949 (K); Cordillera Central, cabeceras del río Otúm, bajando del Nevado de Santa Isabel, páramos de la Laguna del Mosquito, 3820 m alt., 26 Nov. 1946, J. Cuatrecasas 23233 (K). Cundinamarca: Mun. Usme: Laguna Chizaca, hierba creciendo al lado de la carretera que conduce a la laguna, 26 Jul. 1986, A. Betancur & M. Palacio 44 (HUA-47083); Páramo de Chisaca, growing in marsh near lagoon, 3750 m alt., 30 Sep. 1966, T.R. Soderstrom 1273 (K).

Preliminary conservation status.

Vulnerable (VU). Despite the species being known from several collections from the Central and Eastern Cordilleras of the Colombian Andes, the páramos of Colombia are currently facing threats of habitat degradation and loss, principally from mining ( Pérez-Escobar et al. 2018) and so a preliminary conservation status of VU is given.

Etymology.

The varietal epithet refers to the absence of an awn inserted in the dorsal surface of the lemma.

Notes.

Certain specimens were encountered which exhibited a mix of the characters mentioned in the diagnosis for separating D. podophora from D. podophora var. mutica . For example, specimen Cuatrecasas 23233 from the Cordillera Central of Colombia had isomorphic flat leaf blades which formed a basal mat much shorter than the exerted culms but also had awnless spikelets. A few other specimens exhibited the larger habit, i.e. multiple longer culms with longer and wider leaf blades forming tussocks and inflorescences included within sheaths, but with awned spikelets.

Specimens of Deschampsia podophora var. mutica were commonly misidentified as Poa L. in herbaria, most likely due to the lemmas lacking awns. There are very few South American Calamagrostis s.l. that consistently lack awns (see ‘notes’ of Deschampsia santamartensis sp. nov. above) and, of the species not belonging to subsect. Stylagrostis (= Deschampsia ), the closest resembling species is Calamagrostis ecuadoriensis Laegaard (1998), which also has short florets with a pilose rachilla extension and which lack awns. However, C. ecuadoriensis can be differentiated from Deschampsia podophora var. mutica by, amongst other things, a) habit, being small tussocks, 20-30 cm high, with leaves mostly basal; b) culms, panicle branches and pedicels densely hispid; c) panicles narrow, ca.1 cm wide; d) anthers 0.8-1 mm long; e) florets only shortly stipitate, with the stipe <0.15 mm long at the base of the glumes.

Figures

Figure 3. Deschampsia podophora var. mutica. A whole plant B anther C spikelet at maturity with anthers D lemma, abaxial view E palea, abaxial view F upper glume, abaxial view G lower glume, abaxial view H floret I spikelet and pedicel, lateral view J ligule; drawn by Juliet Beentje from the isotype, J. R. I. Wood 5033 (K).