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

Peterson, Paul M., Vega, Isidoro Sanchez, Romaschenko, Konstantin, Giraldo-Canas, Diego & Rodriguez, Nancy F. Refulio, 2018, Revision of Muhlenbergia (Poaceae, Chloridoideae, Cynodonteae, Muhlenbergiinae) in Peru: classification, phylogeny, and a new species, M. romaschenkoi, PhytoKeys 114, pp. 123-206 : 142

5. Muhlenbergia ciliata (Kunth) Trin., Gram. Unifl. Sesquifl. 193. t.5, f.16. 1824. Fig. 4D-G

Podosemum ciliatum Kunth, Nov. Gen. Sp. (quarto ed.) 1:128-129. 1816. Trichochloa ciliata (Kunth) Roem. & Schult., Syst. Veg. 2:386. 1817. Polypogon ciliatus (Kunth) Spreng., Syst. Veg. 1:243. 1825. Type: Mexico, Michoacán, Volcán de Jorullo, Sep, F.W.H.A. Humboldt & A.J.A. Bonpland s.n. (holotype: P-HBK!; isotypes: BAA-1619 ex P!, BM!, P-Bonpl!, US-91918 fragm. ex P!).

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. (holotype: LE?; isotypes: LE-TRIN-1486.01 fragm. ex LE herb. Mertens!, 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-nerved; 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-nerved but appearing five-nerved, the intermediate “nerves” actually rows of short barbs on top of folded epidermal ridges, sometimes with prominent short hairs (scabers) along the lateral nerves, often appearing glabrous without magnification, awns 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 in Ecuador, Peru, Brazil, Bolivia, Brazil and Argentina.

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 spp., Bothriochloa , Eupatorium , Melinus minutiflora P. Beauv., Muhlenbergia bryophilus , M. flexuosa , M. rigida , Puya and Salvia ; 1000-2400 m.

Comments.

Muhlenbergia ciliata is morphologically similar to M. romaschenkoi and can be differentiated from the latter in having short ligules 0.2-0.8 mm long [1.2-3.0 (-5.0) mm long in M. romaschenkoi ], paleas that are glabrous between the veins on the proximal ½ (versus appressed pubescent), 6-13 nodes along the panicle (versus 15-23) and panicles that are 4-12 cm long (versus 7-15 cm long) [ Peterson and Giraldo-Cañas 2011, 2012]. Some individuals of M. ciliata from Peru do not have prominent cilia along the lateral veins that are present in most individuals from North America.

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 clade in Muhlenbergia subg. Muhlenbergia ( Peterson et al. 2010b; Fig. 1B ).

Specimens examined.

Peru. Amazonas: Piedra Grande, near Rio Santo Domingo, 5000 ft alt., 14-19 May 1923, J.F. Macbride 3684 (F, US). Cusco: Urubamba, Ruinas de Macchu Picchu, 2500 m, 27 May 1963, D. Ugent 5356 (US), 2300 m, 11 Apr 1963, C. Vargas C. 14354 (US), Mar 1987, I. Grignon 2306 (AAU, US); Quebrada Termas Macchu Picchu, 25 Mar 1966, C. Vargas C. 17145 (USM). Huánuco: 21 air km NE of Pachitea, 7 km E of Puerto Rancho junction, 9°49'45.9"S, 76°3'12.9"W, 2094 m, 6 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romaschenko 20336 (US); Pachitea, canyon of the Rio Grande, along trail 1 air km NW of Estación Huacachay, 9°50'44.7"S, 75°50'5.2"W, 2323 m, 8 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romaschenko 20378 (US); 2 air km ESE of Eastación Huacachay, 9 °51'34.7"S, 75°50'48.1"W, 1867 m, 7 Mar 2007, P.M. Peterson, R.J. Soreng & K. Romaschenko 20359 (US). Junín: between Tarma and La Merced, 3000 m, 14 Oct 1923, A.S. Hitchcock 22154 (US); Mito, 9000 ft alt., 8-18 Apr 1923, J.F. Macbride 3376 (F, US); Province Huancayo, abajo de Pariabuena, 2000 m, 6 May 1969, O. Tovar 7936 (USM). La Libertad: Bolivar, W of Longotea ca. 0.5 km towards San Vicente on Balsas-Longotea road, 7°2'35.6"S, 77°52'39.8"W, 2487 m, 31 Mar 2008, P.M. Peterson, R.J. Soreng & J. Montoya Quino 21967 (US).

Figures

Figure 1. A, B Maximum-likelihood 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 red occur in South America; scale bar = 2 %.

Figure 4. A-C Muhlenbergia caxamarcensis Laegaard & Sanchez Vega A habit B panicle branch C floret D-G Muhlenbergia ciliata (Kunth) Trin D habit E ligule F glumes G floret. Drawings A-C from Laegaard and Sanchez Vega (1990) from holotype collection (S. A. Renvoize & S. Laegaard 4962) D-G from Peterson and Annable (1991) drawn from P. M. Peterson & C. R. Annable 4541 (WS).