Muhlenbergia pereilema P.M. Peterson, Caldasia 31(2): 293. 2009.

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

21. Muhlenbergia pereilema P.M. Peterson, Caldasia 31(2): 293. 2009.

Fig. 16A-E

Pereilema crinitum J. Presl, Reliq. Haenk. 1(4-5): 233, t. 37, f. a-f. 1830. Type: Panama, T. Haenke s.n. (holotype: PR-198058!; isotypes: BR-0000006886257 [image!], HAL-0107173 [image!], LE-TRIN-1519.01!, M, MO-123263!, PR-849!, W-0029492 [image!], W-0029493 [image!], W-18890238189 [image!]). Basionym.

= Pereilema crinitum var. cirratum E. Fourn., Mexic. Pl. 2: 93. 1886. Type: México, Veracruz, Escamella, Orizaba, 24 Oct 1866, E. Bourgeau 3272 (lectotype, designated here: P-00751681 [image!]; isolectotypes: L-0062313 [image!], S14-29644 [image!], US-996097! ex P).

Description.

Delicate, caespitose, annuals. Culms 15-90 cm tall, decumbent, rooting from flower nodes, mostly smooth and glabrous below the nodes; internodes usually glabrous to scaberulous. Leaf sheaths longer than the internodes, smooth or scaberulous; ligule s 0.5-1 mm long, membranous, eciliate, irregularly erose; blades 5-15 cm long, 2-3(-5) mm wide, flat, acuminate, auriculate near base; auricles 1-1.5 mm long, falcate. Panicles 5-20 cm long, 1-3 cm wide, spiciform, linear, continuous or interrupted; primary branches 0.5-3.5 cm long, appressed, the spikelets arising just above the sterile spikelets or bristles; bristles 2-4 mm long, antrorsely scabrous; pedicels 0.1-0.2 mm long, oblong, arising just above the bristles. Spikelets 1.5-2.6 mm long, greenish to stramineous, subtended by an involucre of persistent bristles, disarticulation below the glumes; glumes 0.8-1.5 mm long, equal, narrowly awl-shaped, awned, the awns 1-3 mm long; lemmas 1.5-2.6 mm long, ovate, keeled, 3-veined, with appressed hairs below, lateral veins close to margins, scabrous, apex acuminate, awned, the awns (15-)20-30 mm long, flexuous, callus hairy, the hairs 0.3-1 mm long; palea similar to lemma; stamens 3, anthers 0.5-0.7 mm long, yellow; style 1. Caryopses 0.8 mm long, ellipsoid, with adherent pericarp. 2n = 20 ( Pohl and Davidse 1971).

Distribution.

Muhlenbergia pereilema ranges from throughout México to Central (Costa Rica, El Salvador, Guatemala, Honduras, México, Nicaragua, and Panama) and South America ( Peterson et al. 2001).

Ecology.

This species occurs on grassy slopes and rocky roadsides, ravines, and barrancas in tropical and oak-pine forests; 50-2450 m.

Comments.

Muhlenbergia pereilema can be separated from M. plumiseta in having persistent, scabrous bristles (plumose in M. plumiseta ) and wider panicles (1-3 cm in M. pereilema and 0.2-0.6 cm wide in M. plumiseta ) [ Pohl 1994B; Herrera Arrieta et al. 2010; Herrera Arrieta and Peterson 2018]. This species forms a clade with M. beyrichiana Kunth and M. plumiseta within M. subg. Muhlenbergia ( Peterson et. al. 2021).

Specimens examined.

Costa Rica. Alajuela: Atenas, Balsa, alrededores de las Escuela Centroamericana de Gandería, J. Gómez-L 6127 (CR); 1 km S Carrizal, open roadside in coffee plantation, R.W. Pohl & G. Davidse 11502 ( US, CR); La Garita, dam in the canyon of the Rio Grande de Tarcoles, R.W. Pohl & G. Davidse 11494 ( US, CR); 1 km N of Grecia, R.W. Pohl & G. Davidse 11523 ( US, CR). Cartago: Roadside N of Puente Negro, N of Orosi, R.W. Pohl & M. Lucas 13153 (MO, CR); Turrialba, Près de la station de Juan Viñas, H. Pittier 1759 (CR); San Juan Norte, R. W. Pohl & G. Davidse 11435 ( US, CR); vicinity of Finca Las Concavas, P.C. Standley 41551 ( US). Heredia: Orillas de la vía férrea a Heredia, A.M. Brenes 13284 (CR); Barva, bordes del Río Segundo, J. León 415 (CR); El Gallito de Heredia, M. Valerio 540 (CR). Puntarenas: Paturage a Boruca, A. Tonduz 3689 (CR); Savannas de Boruca, H. Pittier (Tonduz, A.) 4450 ( US, CR); Boca de Barranca, M. Montiel s.n. (USJ); Bord du chemin a Mano de Tigre, H. Pittier (Tonduz, A.) 4627 ( US, CR). San José: Acosta, camino a Bajo Palma, J.F. Morales 7439 (INB, MO); Puriscal, Alto La Escalera, a lo largo del camino entre San Ignacio y Guaitil, cuenca del Pirris-Damas. Valle del Candelaria, Alto La Escalera en el camino a Bajo Arias y La Cruz, J.F. Morales & B. Hammel 6049 (MO, INB, CR); Acosta, Cuenca del Pirris-Damas, Cerros de Caraigres, cabeceras del Río La Mesa, cerca Ceiba Este, J.F. Morales & J.F. Corrales 6032 (MO, INB); Mora, Colón, le long des chemins dans la vallée du rio Jaris, prés de Pacaca, H. Pittier 3329 (CR); Mora, Colón, en la orilla del camino de lastre que va de Brasil a Ciudad Colón, S. Lobo 2309 (CR); Escazú, San Antonio, D. Santamaría 3648 (INB, MO); Bordes líneas férreas San José-Guadalupe, A. Tonduz 709 (CR); Hacienda La Esperanza, La Palma, O. Jiménez 973 ( US, CR); Sur un rocher au bord du rio Virilla, sous le pont du F. C. R., près San Juan, A. Tonduz 17556 (CR); 13 km N of San Isidro de El General along carretera interamericana, R. W. Pohl & G. Davidse 11626 ( US, CR); San Pedro, W.A. Archer 3888 ( US); Tibas, collected along the Río Virilla about 1 km S of Santo Domingo, J. Taylor 17313 (MO). El Salvador. Ahuachapán: Ahuachapán, S.A. Padilla 134 ( US); San Benito, al N de la cima del cerro La Olla, E. Sandoval & Chinchilla 767 (LAGU, MO). La Libertad: Nueva San Salvador, Jardin Botanico La Laguna, W.G. Berendsohn 1003 (LAGU, MO); Boqueron del Volcán de San Salvador, L. E. González 1851 (MO, ITIC). San Salvador: San Salvador, S. Calderón 494 (MO); San Martin, S. Calderón 1902 ( US); Cerro el Guayabal, S. Calderón 1964 ( US). Guatemala. Alta Verapaz, Coban, H. von Türckheim 743 (MO); Cobán, H. von Türckheim 1362 (MO); H. von Türckheim 1509 (MO, US); Area of mixed forest and clearings, hills about 10 km south of Coban, L. O. Williams et al. 40051 ( US); Finca aved near Coban, W. Popenoe 903 ( US). Chimaltenango: along road from Chimaltenango to San Martin Jilotepeque, P.C. Standley 57894 ( US). Chiquimula: Volcan Ipala, near Amatillo, bordering lake on top, J.A. Steyermark 30491 ( US). Huehuetenango: Thickets and forest in deep canyon of a tributary of Rio Blanco, about 5 km W of Aguacatan, L.O. Williams et al. 22338 ( US). Jalapa: vicinity of Jalapa, pine-oak forest, P.C. Standley 76749 ( US). Jutiapa: Volcan Chingo, J. Donnell Smith 3673 ( US). Guatemala: Guatemala City, A.S. Hitchcock 9050 ( US); Guatemala City, rocky hill, A.S. Hitchcock 9031 ( US); Guatemala City, barranca north of Guatemala city, W. Popenoe 733 ( US); San Antonio, Las Roces, Rojas 385 ( US). Santa Rosa: Chupadero, J. Donnell Smith 3914 ( US); Cerro Redondo, J. Donnell Smith 6274 ( US). Solola: Mixed forest area, mountain slopes above Lake Atitlan, about 3-5 km W of Panajachel, L.O. Williams et al. 25278 ( US). Honduras. El Paraíso: Yuscarán, la Piedra de Apaguiz, 3.5 km al SE de Danlí, N.P. Estrada 137 (MO, CR, TEFH); Arauca, Las Manos, 5 km N of Las Manos, near Los Limones, R.W. Pohl & M. Gabel 13429 (MO, CR); Road to Danlí, near Río San Francisco, J. R. Swallen 11196 (MO); Road to Yuscaran, J.R. Swallen 11347 ( US). Francisco Morazán: Distrito Central, Cerro el Hatillo, 15 km al NE de Tegucigalpa; bosque premontano húmedo, L.M. Ordóñez 67 (MO); San Antonio de Oriente, quarry above El Zamorano, on road to San Antonio de Oriente, R.W. Pohl & G. Davidse 12505 (MO, CR); vicinity of El Zamorano, along "Wood Road", J.R. Swallen 10821 ( US); In pine woods near Piedra Herrada, Mt. Uyuca region, L.O. Williams 18543 ( US); Drainage of the Rio Yeguare, Moist rocky bank near Agua Amarilla, in oak-pine forest, L.O. Williams & A. Molina R. 14723 ( US). Olancho: Jutiapa Forest Camp, near Salamá. Pine forest on a steep slope above a stream, R.W. Pohl & M. Gabel 13749 (MO, CR). Mexico. Chiapas: Angel Albino Corzo: slopes of Río Cuxtepec, below Finca Cuxtepec, D.E. Breedlove & G. Davidse 54676 (MEXU, CAS). Arriaga: 13 km N of Arriaga along Mex. Hwy. 195, D.E. Breedlove & G. Davidse 54149 (CAS, MO); slope at El Sumidero, 22 km N of Tuxtla Gutierrez, D.E. Breedlove & P.H. Raven 13387 (DS); along ravines 13 km N of Arriaga along Mexican Highway 195, D.E. Breedlove 28278 (MO). Cintalapa: 23 km W of Las Cruces along road to La Mina Microwave Station, D.E. Breedlove & G. Davidse 54092 (CAS, MO). Chiapa de Corzo: above El Chorreadero, D.E. Breedlove & G. Davidse 54032 (MEXU, CAS, MO); 36 km E of Tuxtla Gutierrez, F.W. Gould & S. Hatch 14374 (ISC, DS); Ixhuatán: 2 km al N of Ishuatan, G. Davidse et al. 29641 (MEXU, MO). Ixtapa: intersection of Tuxtla Gutiérrez-San Cristobal de las Casas and Villahermosa, G. Davidse et al. 30104 (MEXU, MO); near Ixtapa, D.E. Breedlove & G. Davidse 54264 (CAS, MO); along Mex Hwy 190 in the Zinacantan paraje of Muctajoc, D.E. Breedlove 13819 (DS). Motozintla: Motozintla de Mendoza, 25-27 km NE of Huixtla along rd to Motozintla SW of Toliman, D.E. Breedlove 28593 (CHAPA, MEXU, DS, MO); Ejido Toliman, sobre la carr. Huixtla-Motozintla. Vega de Arroyo, Gómez et al. 185 (MEXU). Tenejapa: In the paraje of Mahosik’, D.E. Breedlove 16146 (DS). Villa Corzo: Above Colonia Vicente Guerrero on road to Finca Cuxtepec, D.E. Breedlove & L. Strother 46573 (CAS, MO); Above Colonia Vicente Guerrero on road to Finca Cuxtepec, D.E. Breedlove & G. Davidse 54567 (MEXU, CAS, MO). San Fernando: Parque Nacional del Sumidero, 20-22 km NW of Tuxtla Gutiérrez, G. Davidse et al. 29767 (MEXU, MO). Nicaragua. Rivas, Volcán Concepción, Isla Ometepe, plantas propias de la lava, W. Robleto T. 157 (MO, CR). Panama. Coclé, vicinity of Ola, H. Pittier 5046 ( US).

Figures

Figure 16. A-F Muhlenbergia pereilema P. M. Peterson A habit B ligule with auricles C portion of the inflorescence D glumes E floret F stamens, pistil, and lodicules G-L Muhlenbergia plumiseta Columbus G habit H ligule with auricles I portion of the inflorescence J bristles K floret L stamens and pistil. A-F drawn from A. S. Hitchcock 9050 (US) G-L drawn from C. G. Pringle 5962 (US).