Muhlenbergia implicata (Kunth) Trin., Gram. Unifl. Sesquifl. 193: t. 5a, f. 26. 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

10. Muhlenbergia implicata (Kunth) Trin., Gram. Unifl. Sesquifl. 193: t. 5a, f. 26. 1824.

Fig. 8E-H

Podosemum implicatum Kunth, Nov. Gen. & Sp. 1: 127. 1815 (1816). Type: México, Michoacán, near Lake Cuiseo and Puerto de Andaracuas, F.W.H.A. Humboldt & A.J.A. Bonpland s.n. (holotype: B-W!; isotype: P!). ≡ Trichochloa implicata (Kunth) Roem. & Schult., Syst. Veg. 2: 385. 1817 ≡ Agrostis implicata (Kunth) Spreng., Syst. Veg. 1: 262. 1825. Basionym.

= Muhlenbergia erecta J. Presl, Reliq. Haenk. 1:231. 1830, nom illeg. hom., non Muhlenbergia erecta Schreb, 1807. Type: México, Haenke s.n. (holotype: PR!).

Description.

Caespitose slender annuals. Culms 15-50(-70) cm tall, mostly branched below and lax spreading or erect, scaberulous to short-pubescent below the nodes, the nodes 0.4-0.6 mm in diameter just below the inflorescence; internodes 3-9.5 cm long. Leaf sheaths 1.4-9.1 mm long, mostly shorter than the internodes, glabrous to scaberulous; ligules 1-2.5(-3) mm long, membranous to hyaline; blades 3-5(-10) cm long, 1-2.5 mm wide, flat or loosely involute, short pubescent above and mostly glabrous below, margins scabrous. Panicles 7-12(-26) cm long, 3-5(-9.2) cm wide, open, diffuse, with the peduncle included in the sheath, axis scaberulous; primary branches ascending and spreading up to 90° from the culm axis; pedicels 7-11 mm long, capillary, flexuous, delicate, smooth, nodding to reflexed, mostly purplish, thickened just below the spikelet. Spikelets 2.5-3(-4) mm long, purple; glumes 0.2-0.6 mm long, unequal, glabrous, apex truncate to broadly obtuse, often erose; lower glumes 0.2-0.4 mm long, veinless; upper glumes 0.3-0.6 mm long, 1-veined; lemmas 2.5-3(-4.5) mm long, 3-veined, appearing 5-veined because the margins are folded with rows of barbs that resemble extra veins, narrowly lanceolate, scabrous, apex awned and 2-toothed, the teeth to 1 mm long, the awns 8-26 mm long; callus with whitish appressed or spreading pubescence, the hairs up to 0.7 mm long; paleas 2.9-4 mm long, narrowly lanceolate, glabrous, apex acuminate; anthers 0.4-0.9 mm long, purple. Caryopses 1.8-2.7 mm long, narrowly fusiform, brownish. 2n = 20 ( Peterson and Annable 1991).

Distribution.

Muhlenbergia implicata ranges from México to Central (Costa Rica, El Salvador, Guatemala, Honduras, México, Nicaragua, and Panama) and South America ( Peterson and Annable 1991; Peterson et al. 2001). In Mexico, M. implicata is known from Chiapas and Campeche ( Sanchez-Ken 2018).

Ecology.

This species grows on cliffs, canyon walls, and dry to rocky roadsides in open vegetation associated with oak-pinyon-juniper woodlands; (5-) 600-2550 m.

Comments.

Muhlenbergia implicata is a member of M. subg. Pseudosporobolus and is sister to a central Mexican endemic, M. seatonii Scribn. (Fig. 1 ; Peterson et al. 2021).

Specimens examined.

Costa Rica. Alajuela: San Ramon , San Pedro de San Ramon , A.M. Brenes 14966 (CR); San Ramon , Colinas de San Pedro de San Ramon , A.M. Brenes 16704 (CR); San Ramon , San Juan cerca de San Ramón, A. M. Brenes 16852 (CR); Orillas de camino, O. Jiménez 44 (US); Canoas, O. Jiménez s.n. (US); 4 km NW of San Jose, Dry road bank in coffee plantation, R.W. Pohl & G. Davidse 11366 (US); 1 km S of Carrizal. Open roadside in coffee plantation, R.W. Pohl & G. Davidse 11501 (US). Cartago : R.W. Pohl & M. Lucas 13152 (MO). Heredia : M. Grayum 9600 (MO). San Jose : R.W. Pohl & M. Lucas 12997 (MO); Puriscal , 10 km antes de Puriscal, R. Ocampo1123 (CR); San Jose , J.J. Cooper 5996 (US); along railway, A.S. Hitchcock 8511 (US); San Jose , A.S. Hitchcock 8459 (US); San Francisco de Guadalupe , sobre paredón, O. Jiménez 5 (US); 13 km N of San Isidro de El General along the carretera interamericana, busy roadside in forest, R.W. Pohl & G. Davidse 11628 (US); vicinity of Santa Maria de Dota , in potrero, P.C. Standley 41586 (US); vicinity of Santa Maria de Dota , in cafetal, P.C. Standley 41608 (US); vicinity of Santa Maria de Dota , brushy slope, P.C. Standley & J. Valerio 43218 (US). El Salvador. La Libertad : Volcán San Salvador, P. Bernhardt & E.A. Montalvo 79 (MO); Volcano of San Salvador, A.S. Hitchcock 8948 (US). Guatemala. Alta Verapaz: Coban, H. Von Turckheim 3990 (US); Coban, H. Von Turckheim s.n. (US). Chimaltenango: along road from Chimaltenango to San Martin Jilotepeque, P.C. Standley 57892 (US); along road between Chimaltenango and San Martin Jilotepeque , oak forest, P.C. Standley 80877 (US). Guatemala: Guatemala City, A. S. Hitchcock 9030 (US); Guatemala City, A.S. Hitchcock 9013 (US); Barranca north of Guatemala City, W. Popenoe 736 (US). Huehuetenango: Sierra los Cuchumatanes. 8 mi N of Huehuetenango on Pan American hwy CA 1, slopes above Rio , Quercus forest, P.M. Peterson & C.R. Annable 4701 (MO, US); About Laguna de Ocubila , east of Huehuetenango, dry open bank, P.C. Standley 82631 (US); Pine-oak forest region, canyon at head of Rio Chixoy , about 10 km southwest of Huehuetenango, L.O. Williams et al.22548 (US); Barranco in oak forest near Ocubila , 10 km west of Aguacatan , L.O. Williams & T.P. Williams 21785 (US); Open , wet, boggy meadow 3 km S of Huehuetenango, L.O. Williams et al. 22105 (US). Jalapa: Jalapa, P.C. Standley 76829 (MO); vicinity of Jalapa, damp thicket, P.C. Standley 76399 (US); vicinity of Jalapa, P.C. Standley 76410 (US). Sacatepequez: Magdalena, W. A. Archer 3867 (US); Above Pastores , sand along stream, P.C. Standley 60846 (US). Mountains near Santa Maria , Weatherwax 173 (US). Honduras. El Paraíso: Guinope , drainage of the Rio Yeguare , en el pantano, llanos y potreros empantanados de Galeras y Llano de Lizapa , A. Molina 3367 (MO); Cumbre on Yuscaran road, rocky slope in pine forest, P.C. Standley 29360 (US). Francisco Morazan : Distrito Central , Colonia Miraflores, A. Díaz 244A (MO); San Antonio de Oriente , Las Mesas, R.W. Pohl 12521 (MO); Distrito Central , between El Hatillo and Los Jutes, R.W. Pohl & M. Gabel 13791 (MO); Las Casitas, L. Villela 129 (MO); Cerro la Uyuca , La Labranza and vicinity, along trail to summit, moist thicket, trail to La Labranza, P.C. Standley 28299 (US); vicinity of Suyapa, J.R. Swallen 11271 (US); San Antonio del Oriente, J.R. Swallen 10915 (US); Drainage of the Rio Yeguare , L.O. Williams 16905 (US). Mexico. Campeche: Campeche : 2.5 km al oeste de San Francisco Kobén, 5m, 20 Sep 2003, C. Gutiérrez Báez 7909 (MEXU-1338596). Chiapas: 10.5 mi SE of San Cristobal de las Casas, P.M. Peterson & C.R. Annable 4721 (ENCB, MEXU, US); near San Cristobal , A.A. Beetle 3963 (MEXU); W edge of San Cristobal de las Casas, D.E. Breedlove 53975 (NY); 2 mi S of Tuxtla Gutiérrez along road to Villa Flores, D.E. Breedlove & P.H. Raven 13357 (US). La Trinitaria : 20 km S of La Trinitaria, D.E. Breedlove & G. Davidse 55055 (CAS, MO); 6-7 km S of La Trinitaria, G. Davidse et al. 29972 (MO). Ixtapa: near the Zinacantan Paraje of Muctajoc, D.E. Breedlove & G. Davidse 54021 (CAS, MO); near Ixtapa, D.E. Breedlove & G. Davidse 54298 (CAS, MO); near the Zinacantan Paraje of Muctajoc, D.E. Breedlove & G. Davidse 53991 (CAS, MO). Pueblo Nuevo Solistahuacan : Clínica Yerba Buena, 2 km NW de Pueblo Nuevo Solistahuacán, D.E. Breedlove & P.H. Raven 19825 (ENCB, TAES, US). San Cristobal de las casas: S end of the valley of San Cristobal Las Casas, D.E. Breedlove & G. Davidse 54374 (CAS, MO). Teopisca : N of Teopisca, D.E. Breedlove & G. Davidse 54770 (CAS, MO); 7 km NW of Teopisca along hwy. to San Cristobal de las Casas, G. Davidse, M. Sousa, O. Téllez, E. Martinez & J. Davidse 29826 (MO, US); 6 km W of Teopisca, F.W. Gould & S.L. Hatch 14420 (US). Nicaragua. Estelí: Las Pilas, P.P. Moreno 22341 (MO). Jinotega : Mountain slopes and wooded ravines of Cordillera Central de Nicaragua, 2-4 km S of Jinotega, grass in clearing, L.O. Williams et al. 23554 (MO); Jinotega, L. O. Williams et al. 27924 (MO). Panama. Chiriquí: G. Davidse & W.G. D´Arcy 10382 (MO); J.A. Duke 9197 (MO); M. Nee 14135 (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 8. A-D Muhlenbergia diversiglumis Trin. A habit B floret C glumes D ligule E-H Muhlenbergia implicata (Kunth) Kunth E habit F floret G glumes H ligule. A-D drawn from P. M. Peterson & C. R. Annable 4158 (US, WS). E-H drawn from P. M. Peterson & C. R. Annable 4598 (US, WS).