Muhlenbergia ciliata (Kunth) Trin., Gram. Unifl. Sesquifl. 193. t.5, f.16. 1824.

Peterson, Paul M., Herrera Arrieta, Yolanda, Lobo Cabezas, Silvia & Romaschenko, Konstantin, 2023, Taxonomic revision of Muhlenbergia (Poaceae, Chloridoideae, Cynodonteae, Muhlenbergiinae) in Central America: phylogeny and classification, PhytoKeys 230, pp. 1-106 : 1

5. Muhlenbergia ciliata (Kunth) Trin., Gram. Unifl. Sesquifl. 193. t.5, f.16. 1824.

Fig. 6A-D

Podosemum ciliatum Kunth, Nov. Gen. Sp. (quarto ed.) 1:128-129. 1816. Type: México, Michoacán, Volcán de Jorullo, Sep, F.W.H.A. Humboldt & A.J.A. Bonpland s.n. (lectotype, designated here: P-00077293 [image!]; isolectotypes: BAA-1619 ex P!, BM!, P-00129654 [image!], US-91918 fragm. ex P!). ≡ Trichochloa ciliata (Kunth) Roem. & Schult., Syst. Veg. 2:386. 1817. ≡ Polypogon ciliatus (Kunth) Spreng., Syst. Veg. 1:243. 1825. Basionym.

= Muhlenbergia adspersa Trin., Mém. Acad. Imp. Sci. Saint-Pétersbourg, Sér. 6, Sci. Math., Seconde Pt. Sci. Nat. 4(3-4):291. 1841. Type: Peru, Lima, ex herb. C.H. Mertens s.n. (lectotype, designated here: LE-TRIN-1486.01 fragm. ex LE herb. Mertens!; isolectotype: US-87236 fragm. ex LE herb. Mertens!).

Description.

Sprawling, slender annuals. Culms 8-30(-50) cm tall, glabrous, filiform, often tufted, freely branching at lower nodes; 0.2-0.5 mm diameter just below the inflorescence; internodes 6-42 mm long. Leaf sheaths (8-)20-44 mm long, glabrous or sparsely pilose along the margins, shorter than the internodes; ligules 0.2-0.8 mm long, a ciliate membrane; apex truncate; margin with a tuft of hairs up to 1 mm long; blades 1-4 cm long, 0.6-1.4 mm wide, flat or loosely involute, often sparsely pilose above, glabrous below. Panicles 4-12 cm long, 1.8-5.0 cm wide, terminal, densely flowered; primary branches 1.5-3.7 cm long spreading and reflexed at maturity up to 90° from the rachises, one per node; pedicels 0.5-3 mm long, glabrous, appressed, erect; nodes 6-13 per panicle. Spikelets appressed to the branches, overlapping; glumes 0.7-1.7 mm long, subequal, glabrous, 1-veined; apex acuminate, often mucronate; the mucro up to 0.5 mm long; lower glumes 0.7-1.5 mm long; upper glumes 0.8-1.7 mm long; lemmas 1.8-2.5 mm long, lanceolate, slender, awned, strongly 3-veined but appearing five-veined, the intermediate “nerves” actually rows of short barbs on top of folded epidermal ridges, sometimes with prominent short hairs (scabers) along the lateral veins, often appearing glabrous without magnification, awns (1-)5-11(-18) mm long, flexuous; callus minutely short pubescent; paleas 1.6-2.4 mm long, narrowly lanceolate, glabrous; anthers 0.3-0.5 mm long, yellowish. Caryopses 0.8-1.8 mm long, narrowly fusiform, brownish. 2 n = 20.

Distribution.

Muhlenbergia ciliata is found throughout México and Central America (Costa Rica, El Salvador, Guatemala, Honduras, México, Nicaragua, and Panama) to Ecuador, Peru, Brazil, Bolivia, and Argentina ( Peterson and Annable 1991; Peterson et al. 2001).

Ecology.

Muhlenbergia ciliata is found on moist to dry soils usually beneath taller vegetation, sandy drainages, steep rocky slopes, rock outcrops, and disturbed roadsides in woodlands with Acacia , Agave , Andropogon , Bidens , Baccharis ssp., Bothriochloa , Eupatorium , Melinus minutiflora P. Beauv., Muhlenbergia bryophilus , M. flexuosa , M. rigida , Puya , and Salvia ; 1000-2400 m.

Comments.

Muhlenbergia ciliata can be differentiated from M. tenella in having lemmas with ciliate margins (not ciliate in M. tenella ), reflexed and spreading panicles branches (tightly appressed panicle branches in M. tenella ), regular, alternating leaf blade insertion (secund in M. tenella ) [ Peterson and Annable 1991; Peterson and Giraldo-Cañas 2011, 2012].

Muhlenbergia ciliata is closely related to M. pectinata C.O. Goodd. (North America) and M. tenella (Kunth) Trin. (North America, Central America, and Colombia) [ Peterson and Annable 1991]. These three species form a strongly supported clade in M. subg. Muhlenbergia (Fig. 1 ; Peterson et al. 2010b; Peterson et al. 2021).

Specimens examined.

Costa Rica. San José: J.F. Morales 6707A (MO); Cerro de Piedra Blanca, above Escazú, P.C. Standley 32486 ( US); Cord. Talamanca, 14 km S of Division along the Interamerican Highway, roadside through oak forest, road fill, R.W. Pohl & G. Davidse 11616 ( US). El Salvador. San Salvador: Volcano of San Salvador, A.S. Hitchcock 8938 ( US). Guatemala. Alta Verapaz: Coban, Unter Kiefernwald, H. Von Turckheim 3989 ( US). Guatemala: Guatemala city, dry hill, A.S. Hitchcock 9061 ( US). Quetzaltenango: km 15.5, M. de Koninck, M. 227 ( US). Huehuetenango: San Juan Ixcoy, Sierra de los Cuchumatanes, 3 mi N of San Juan Ixocy on Hwy 9N, P.M. Peterson & C.R. Annable 4689 (MO); Huehuetenango, P.M. Peterson & C.R. Annable 4681 (MO). Sacatepequez: Magdalena, W.A. Archer 3865 ( US); Volcano Agua, open ground near Antigua, A.S. Hitchcock 9135 ( US); Volcano Agua, A.S. Hitchcock 9136 ( US). Totonicapán: San Francisco El Alto, W.E. Harmon 4555 (MO). Zacapa: Forested slopes, Sierra de las Minas, near summit of mountain, between Rio Hondo and Finca Alejandria, J.A. Steyermark 29683 ( US). Honduras. Copan: Sta. Rosa de Copan, W.A. Archer 3838 ( US). Francisco Morazán: Santa Lucía, Quebrada Hierba Buena, R. Clotter 87 (MO); Tatumbla, Cerro Uyuca, I. Cruz 93 (MO); Tatumbla, Cerro Uyuca, R.W. Pohl & M. Gabel 13414 (MO); Distrito Central, El Hatillo, R.W. Pohl & M. Gabel 13463 (MO); Distrito Central, between El Hatillo and Los Jutes, R.W. Pohl & M. Gabel 13790 (MO); Valle Angeles, R. Ramos 99 (MO); Valle de los Angeles, El Balmoral, C. Román 23 (MO); Drainage of the Rio Yeguare, L. O. Williams 17001 ( US); Cerro de Uyuca, along trail from Las Flores to La Labranza, P.C. Standley 27380 ( US); San Antonio del Oriente, J.R. Swallen 10916 ( US); Mt. Uyuca, J.R. Swallen 11177 ( US). Mexico. Chiapas: Cacahoatán: 3 km NE of Huixtla on hwy to Motozintla, W.D. Stevens & E.M. Martínez 25671 (MO). Ocozocoautla de Espinosa: 13 km E of Ocozocoautla on Rte. 190, then N on road to Aguacera, M.J. Huft el al. 2252 (MO). Ixtapa: 1 km W of Ixtapa, F.W. Gould 12713 (ENCB). Jitotol: about 10 mi NE of Bochil on Hwy 195, J.R. Reeder & C.G. Reeder 6075 (ARIZ, ENCB, MO); 4 km SE of Jitotol along road to Bochil, G. Davidse et al. 29663 (MEXU); Slope, 10 km N of Jitotol near Rio Hondo, D.E. Breedlove & G. Davidse 55155 (CAS); Santa Isabel near Jitotol, A. A. Beetle M-4091 (MEXU). Ruíz: camino de El Zopilote a San Juan Corapan, A. Ramos 291 (MEXU). Teopisca: Belem, 8 km NW of Teopisca along hwy. to San Cristobal de las casas, G. Davidse et al. 29771 (MEXU); 8.2 mi SE de San Cristóbal de las Casas, P.M. Peterson & C.R. Annable 4679 ( US); 10.5 mi SE of San Cristobal de las Casas, P.M. Peterson & C.R. Annable 4717 (ENCB, MEXU, US); Venustiano Carranza: 3 mi S of Aguacatenango along rd to Pinola Las Rosas, D. E. Breedlove & P. H. Raven 13458 ( US). Nicaragua. Estelí: Darailí, W.D. Stevens 15913 (MO). Panama. Chiriquí: vicinity of Boquete, from Boquete to 3mi N, W.H. Lewis et al. 332 (MO).

Figures

Figure 1. A, B Bayesian tree inferred from combined plastid (ndhA intron, rps 16 - trnK, rps 16 intron, rps 3, and rpl 32 - trnL) and ITS sequences. Thick branches indicate posterior probabilities of 0.95 - 1; species in bold occur in Central America; Scale bar: 2 %.

Figure 6. A-D Muhlenbergia ciliata (Kunth) Trin. A habit B floret C glumes D ligule E-F Muhlenbergia vaginata Swallen E habit F ligule G glumes H floret. A-D drawn from P. M. Peterson & C. R. Annable 4541 (US, WS) E-F drawn from P. M. Peterson & C. R. Annable 4111 (US, WS) both used in Peterson and Annable (1991).