Muhlenbergia phalaroides (Kunth) P.M. Peterson, Caldasia 31(2): 294-296, f. 7 A-B . 2009.

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 : 170-173

16. Muhlenbergia phalaroides (Kunth) P.M. Peterson, Caldasia 31(2): 294-296, f. 7 A-B. 2009. Fig. 11E, F

Lycurus phalaroides Kunth, Nov. Gen. Sp. (quarto ed.) 1: 142. 1815 (1816). Type: Mexico, Michoacán, near Valladolid, Alberca de Palangeo and Patzcuaro, Sep, F.W.H.A. Humboldt & A.J.A. Bonpland s.n. (holotype: P-00669405 [image!]; isotypes: B-W-1630, BM!, BAA-1530!, US-91988 fragm. ex P-BONPL!, US-610837 fragm. ex LE-TRIN!).

Muhlenbergia lycuroides Vasey ex Beal, Grass. N. Amer. 2: 239. 1896. Type: Mexico, Jalisco, Guadalajara, Jul-Oct 1886, E. Palmer 489 (holotype: MSC; isotypes: GH-00023916 [image!], LE, MEXU, MO-2972929!, NDG-07247 [image!], NY, P-00644181 [image!], P-00644182 [image!], S14-29628 [image!], US-822925!, US-81642!, YU-000898 [image!]).

Lycurus phleoides var. brevifolius Scribn. ex Beal, Grass. N. Amer. 2: 271. 1896. Type: Mexico, Jalisco, plains of Guadalajara, 23 Oct 1889, C.G. Pringle 2470 (lectotype: MSC, designated by C. Reeder, Phytologia 57(4): 288. 1985; isolectotypes: BAA!, GH, MEXU, MO-2972926!, NY!, P-00644183 [image!], P-00644184 [image!], US-996049!, W-18900000580 [image!], W-19160029092 [image!]).

Description.

Perennials , intricately branched near base. Culms 10-30 cm tall, erect, mostly glabrous, usually decumbent and sprawling below, bent at the pubescent to short pilose nodes; internodes 0.4-10 (-15) cm long, pubescent to short pilose. Leaf sheaths much shorter than the internodes above, hyaline near the margins, pilose near summit; ligules 0.4-1 mm long, membranous, apex truncate to deltoid, often erose and lacerate; blades 0.5-6.5 cm long, 0.5-1.2 mm wide, shorter near the base of culms, flat, folded or loosely involute, lanate above and glabrous or with scattered, short appressed hairs below, margins whitish-thickened, apex navicular, occasionally with a short seta, seta usually less than 2 mm long. Panicles 1.5-6.5 cm long, 3-8 mm wide, spiciform and spike-like, densely flowered, often interrupted below with only a few spikelets, terminal or axillary; rachis lanate to hispid, the short hairs antrose or appressed; branches 1.5-7 mm long, very short, the spiklets usually in pairs, rarely 1 or 3 per terminal branch, when in pairs the lower short-pedicelled spikelet perfect, staminate or sterile and the upper longer-pedicelled spikelet usually perfect; pedicels 0.3-1.4 mm long; disarticulation usually at the base of the pedicel, each spikelet falling as a unit leaving a small cup-like tip. Spikelets 3-4 mm long, stramineous with plumbeous mottles, sometimes additionally with purplish mottles; glumes 1-2.1 mm long, shorter than the lemma, subequal, 1-3-veined; lower glumes commonly 2 or 3-veined, usually 2-awned, ocassionally 1 or 3 awned, the awns 1-3 mm long, equal or subequal, scabrous, recurved; upper glumes commonly 1-veined, usually 1-awned, the awns 1-2.5 mm long; lemmas 3-4 mm long, narrowly lanceolate, 3-veined, margins hirsute to lanate and occasionally the lower ½ sparsely hairy, the hairs 0.1-0.3 mm long, apex usually awned, occasionally unawned or mucronate, the awns 1-3 mm long; paleas 2.8-3.8 mm long, hairy between the veins, the veins occasionally extending as mucros; anthers 1.3-2 mm long, yellowish. Caryopses 1.7-2 mm long, fusiform, brownish.

Distribution.

Muhlenbergia phalaroides ranges from Mexico to South America where it is found in Argentina, Bolivia, Columbia, Ecuador and Peru ( Reeder 1985; Sánchez and Rúgolo de Agrasar 1986; Davidse and Pohl 1994).

Ecology.

This species occurs in open grasslands and savannahs on steep rocky slopes flats and along disturbed irrigation canals in deep clayish-loam to sandy soils associated with Baccharis , Berberis , Cheilanthes , Condalia , Dodonaea viscosa , Eragrostis , Jarava ichu Opuntia , Muhlenbergia cenchroides , M. rigida , Nassella , Plantago , Puya and Sporobolus indicus (L.) R. Br.; 2800-3500 m.

Comments.

Muhlenbergia phalaroides is morphologically similar to M. phleoides (Kunth) Columbus, known in south-western U.S.A. and Mexico and M. alopecuroides found in south-western U.S.A., Mexico and disjunct in Argentina and Bolivia ( Davidse and Pohl 1994, Renvoize 1998, Reeder 2003; Peterson and Giraldo-Cañas 2012). Muhlenbergia alopecuroides differs from M. phalaroides in having leaf blades with terminal seta (3-)4-7(-12) mm long and ligules(2-)3-12 mm long whereas M. phleoides differs in having auriculate ligules 1-2 mm long ( Reeder 1985, 2003). These morphological differences are perhaps better recognised at the subspecific level but there have been no population studies comparing these three species, other than Peterson and Morrone (1997) who investigated populations of only the amphitropical, M. alocpecuroides [as Lycurus setosus ].

Muhlenbergia phalaroides lies within M. subg. Pseudosporobolus , aligning with M. alopecuroides and M. phleoides (Peterson and Romaschenko, in prep.). Many members of this subgenus have narrow panicles, plumbeous spikelets with unawned, mucronate or short-awned lemmas ( Peterson et al. 2010b).

Specimens examined.

Peru. Ancash: 15 Mar 1947, J. Infantes Vera 1170 (LIL). Ayacucho: Huanca Sancos, 27 km NW of Putajasa and 3 km S of Sacsamarca, 13°57'51.1"S, 74°18'41.5"W, 3650 m, 25 Feb 2002, P.M. Peterson 16277, A.A. Cano, M.I. LaTorre, A. Ramirez & D. Susanibar (US, USM). Cusco: Canchis, Hacienda Occobamba, 3450 m, 4 Apr 1950, C. Vargas C. 9410 (CUZ, US); Prov. Quispicanchis, Pikillacta, 3250 m, 28 Apr 1946, C. Vargas C. 6033 (CUZ, US). Huancavelica: near Huancayo, 3270 m, 1 Apr 1952, O. Tovar 344 (US, USM); Sacxhahuajta, a 6 km de Conaica, 3600 m, 3 Apr 1952, O. Tovar 939 (US, USM). Junín: Huancayo, 3317 m, Mar 1943, J. Soukup 1900 (COL, LIL, US); Prov. Huancayo, Agua de las Virgenes, 3270 m, 1 Apr 1951, O. Tovar 344 (MOL, USM); Tarma, between La Oroya and La Merced, 3000 m, 24 Oct 1923, A.S. Hitchcock 22169 (US).

Figures

Figure 11. A-D Muhlenbergia peruviana (P. Beauv.) Steud A habit B ligule C glumes D floret E, F Muhlenbergia phalaroides (Kunth) P. M. Peterson E panicle F spikelet. Drawings A-D from Peterson and Annable (1991) drawn from P. M. Peterson & C. R. Annable 4739 (WS) E, F from Giraldo-Canas and Peterson (2009) drawn from S. Laegaard 71419 (AAU).