Taxonomic revision of Muhlenbergia (Poaceae, Chloridoideae, Cynodonteae, Muhlenbergiinae) in Central America: phylogeny and classification Author Peterson, Paul M. https://orcid.org/0000-0001-9405-5528 Department of Botany MRC- 166, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013 - 7012, USA peterson@si.edu Author Herrera Arrieta, Yolanda https://orcid.org/0000-0003-3814-6518 Instituto Politecnico Nacional, CIIDIR Unidad-Durango-COFAA, Durango, C. P. 34220, Mexico Author Lobo Cabezas, Silvia https://orcid.org/0009-0007-8100-2559 Herbario Nacional, Museo Nacional de Costa Rica, Apartado Postal 749 - 1000, San Jose, Costa Rica Author Romaschenko, Konstantin https://orcid.org/0000-0002-7248-4193 Department of Botany MRC- 166, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013 - 7012, USA text PhytoKeys 2023 2023-08-03 230 1 106 http://dx.doi.org/10.3897/phytokeys.230.103882 journal article http://dx.doi.org/10.3897/phytokeys.230.103882 1314-2003-230-1 365B97AE96F45DB295043BF02F4AF4BE 11. Muhlenbergia lehmanniana Henrard, Meded. Rijks-Herb. 40: 49. 1921. Fig. 10G-K = Muhlenbergia attenuata Swallen, Ann. Missouri Bot. Gard. 30 (2): 138. 1943. Type: Panama , Chiriqui , El Boquete, foothills, 1000-1300 m, A.S. Hitchcock 8174 (holotype: US-995843!). = Muhlenbergia multinodis Aspl., Bot. Not. 1939: 796. 1939. Type: Colombia, Cauca, Popayan , El Tambo, 1700 m, 22 Jun 1938, Sneidern 1323 (holotype: S-R-3665 [image!]; US-2383833 fragm. ex S!). Type . Colombia , Cauca , Popayan , F.C. Lehmann 1267 ( holotype : L-0044745 [image!]; isotypes: K-000308934 [image!], NY-00381489 [image!], US-72979 fragm. ex L!, US-72977 fragm. ex L!, US-72978 fragm. ex K!) . Description. Caespitose perennials covered in old sheaths. Culms (72-)90-130(-167) cm tall, erect, compressed-keeled near base, glabrous to scaberulous below the nodes; internodes glabrous. Leaf sheaths tightly imbricate below, golden yellow with age, not basally shredded; ligules 10-25 mm long, membranous, somewhat firm below; apex acuminate; sheath auricles lacking or rarely rudimentary up to 0.1 mm long; blades 20-40 cm long, 1-4 mm wide, flat to folded, scaberulous to scabrous, apex becoming narrow and threadlike. Panicles 19-45 cm long, 3-6 cm wide, dense and narrow, golden, golden-brown or purplish-green; primary branches mostly 3.5-14 cm long, and up to 19 cm long below, ascending and appressed, naked below; pedicels 0.7-3.5 mm long, scaberulous. Spikelets 2.5-3.8 mm long, erect; glumes 2.5-3.8 mm long, about equal, sometimes the upper glume, both longer than the lemmas, 1-veined, occasionally 2 or 3-veined, hispid; apex obtuse to dentate, usually mucronate, the mucro up to 0.3 mm long; lemmas 2-3.3 mm long, pilose along the veins and margin on lower 2/3, awned from just below the apex; apex obtuse, the awns 10-20 mm long, flexuous and minutely scabrid; callus with short hairs; paleas 2.3-3.2 mm long, usually shorter than the lemma, hairy between the veins on the lower 1/2 ; anthers 1.4-1.6 mm long. Caryopses 1.2-1.3 mm long, fusiform, glabrous, light brown. 2 n = 20 +2b ( Reeder 1994 ). Figure 10. A-F Muhlenbergia versicolor Swallen A habit B ligule C glumes D lemma E palea F stamens, pistil, and lodicules G-K Muhlenbergia lehmanniana Henrard G habit, H ligule I glumes J floret K stamens, pistil, and lodicules. A drawn from G.B. Hinton 2324 (US-1840807) B-F drawn from G.B. Hinton 14808 (US-1842654) G-K drawn from H. Pittier 1468 (US). Distribution. Muhlenbergia lehmanniana ranges from Central America in Costa Rica, Honduras, and Panama to South America in Columbia, Ecuador, and Venezuela ( Giraldo-Canas and Peterson 2009 ). Ecology. This species occurs on gentle to steep slopes, ravines, gravelly sites, and disturbed sites in humid tropical forests with Pinus and Quercus ; 600-2200 m. Comments. Muhlenbergia lehmanniana is morphologically similar to M. maxima Laegaard & Sanchez Vega, a Peruvian endemic. However, M. lehmanniana differs from M. maxima in having longer lemmatal awns (12-20 mm long versus 4-9 mm long in M. maxima ) and longer ligules (10-25 mm long versus 3-5 mm long in M. maxima ) [ Peterson et al. 2018 ]. Muhlenbergia lehmanniana is a member of M. subg. Trichochloa ( Peterson et al. 2010b ; 2021 ). There is not much genetic variation among all members of M. subg. Trichochloa in Peterson et al. (2018 , 2021 ). Specimens examined. Costa Rica . Basamento de Fila Lleskila, L.D. Gomez et al. 23244 (MO). Alajuela : San Ramon , San Pedro de San Ramon , cerca del Rio Barranca, A.M. Brenes 21415 (CR); 6 km S of Los Cartagos by road, R.W. Pohl & G. Davidse 11504 ( US ); 12 km SW of San Ramon along the Carretera Interamericana, R.W. Pohl & G. Davidse 11511 ( US ). Cartago : El Guarco, F. Solis 618 (CR); Oreamuno, in Monte Irazu , A.S. Oersted 14012 ( US ), 14471 ( US ); Paraiso , Las Concavas, C.H. Lankester 676 ( US ); 5 km E of Paraiso , R.W. Pohl & G. Davidse 11390 ( US ). Puntarenas : Coto Brus, Z.P. Las Tablas. Cuenca Terraba-Sierpa, el tajo, colectando a orillas del camino, E. Alfaro 2593 (MO); Coto Brus, Z.P. Las Tablas, Cuenca Terraba-Sierpe , Cerro Pando, colecta en bosque y orillas de potreros E. Alfaro et al. 925 (MO); Coto Brus, Z.P. Las Tablas. Cuenca Terraba-Sierpe , Cerro Pando, colecta en bosque y orillas de potreros, E. Alfaro et al. 931 (MO); Coto Brus, Z.P. Las Tablas, E. Alfaro 925 (INB); Coto Brus, Z.P. Las Tablas, E. Alfaro 931 (INB); Coto Brus, Finca Cafrosa, 2.5 km al E del Progreso, Cerro Pelon , E. Alfaro 2593 (INB); Buenos Aires, Ujarras, El Carmen, Sabanas de Murur Bisuk, estribaciones de Cerro Amu, G. Herrera 3593 (INB); Buenos Aires, P.N. La Amistad, Cuenca terraba-Sierpe , Violey, Sabanas Esperanzas, L. Gonzalez & A. Garita 1196 (MO); Buenos Aires, R.I. Ujarras-Salitre-Cabagra , Cuenca Terraba-Sierpa , Salitre, Cerro Sipar, L. Gonzalez & A. Garita 1215 (MO); Monteverde, 10 km S Monteverde on road to InterAmerican Highway, area of spring, W. Haber & W. Zuchowski 9660 (MO); Golfito, P.N. Corcovado, Peninsula de Osa, Dos Brazos de Rio Tigre, Jimenez , Cuenca superior del Rio Madrigal, margen derecha, G. Herrera & C. Fallas 4710 (MO, INB); Buenos Aires, Ujarras , El Carmen, Sabanas de Murur Bisuk, estribaciones de Cerro Amu , G. Herrera & W. Gamboa 3593 (MO); Buenos Aires, Violey, Sabanas Esperanzas, L. Gonzalez 1196 (INB); Buenos Aires, Salitre, Cerro Sipar, L. Gonzalez 1215 (INB); Parrita, Cuenca del Naranjo y Paquita, Fila Chonta, La Virgen, sector SE, Fila entre la vuelta del Pallo , cabeceras Rio Palo Seco y Fila Chonta, J. F. Morales & R.J. Abarca 6294 (MO); Buenos Aires, Potrero Grande, A. Rodriguez 9744 (INB); Buenos Aires, Potrero Grande, A. Rodriguez 9835 (INB); Boruca, Savanes de Boruca, Soc. ex. San Jose 449 (CR); Buenos Aires, Potrero Grande, D. Solano 2871 (INB); Buenos Aires, M. Valerio 873 (CR); Monteverde, 10 km S Monteverde on road to Inter American Highway, area of spring, W. Haber 9960 (INB); Coto Brus, Savanas de Canas Gordas, H. Pittier 7355 ( US ); Coto Brus, Savanes de Canas Gordas, H. Pittier 11019 (MO); Coto Brus, Savanas de Canas Gordas, H. Pittier 7358 ( US ); Borde de chemin de Mano de Tigre, H. Pittier 4630 ( US ); San Jose : Perez Zeledon , along Carretera Interamericana, S slope Cerro de la Muerte, between km 125 and km 117, M. Grayum & B. Hammel 9580 (MO, INB); Aserri, bosque primario y tacotales en la Fila El Alto, J.F. Morales 3390 (INB); Aserri, Faldas SE Fila Aguabuena, entre Quebrada Ceniza y Quebrada Sopapo, camino a Bijagual, J.F. Morales 6863 (INB, CR); Acosta, Alto Reflis, Falda NE, Fila de Cal, J.F. Morales 8764 (INB); Escazu , San Antonio, J. Gonzalez 2886 (INB); Aserri, Cuenca del Pirris-Damas, Cerros Caraigres, Falda S, Quebrada Concha, en el camino viejo a Bijagual, J.F. Morales 5915 (MO); Aserri, Cuenca del Pirris-Damas. Ceiba Alta, Cuest Pacayas, Quebrada Pacayas, charrales residuales, J.F . Morales 6759 (MO, INB); 6 km by road N of San Pablo, N of San Marcos, open dry pasture on a hilltop, R.W. Pohl & M. Lucas 13142 (MO); Acosta, Cerro Leon , camino hacia Fila Aguabuena, R. Chacon et al. 190 (CR); Santa Ana, Z.P. Cerros de Escazu , Alto Cana Quemada, A. Estrada et al. 3241 (CR); Cercanias de Division , Carretera Interamericana Sur, J. Gomez-L . 3460 (USJ); Acosta, Cuenca del Rio Pirris-Damas , Fila del Naranjal, sendero a la Escuadra, J.F. Morales 7459 (CR, INB, MO); Acosta, Cerro Leon . Camino hacia Fila Aguabuena, A. Quesada et al. 741 (CR); Acosta, Cerro Leon . Camino hacia Fila Aguabuena, J. Sanchez et al. 1170 (CR); 3 km SSE of Villa Colon, R.W. Pohl & G. Davidse 11399 ( US ); 13 km N of San Isidro de El General along the Carretera Interamericana, R.W. Pohl & G. Davidse 11631 ( US ). Honduras . Comayagua : Ojo de Agua, orilla Rio Humuya, 30 km N de ciudad Comayagua, bosque de vega tropical rodeado de pinares, C. Nelson et al. 6818 (MO). Panama . Chiriqui : In bare clay of steep artificial roadside bank below coffee finca. Western slope of first ridge east of Quebrada Zumbona, opposite east side of Cerro Pando, 7 km (by air) northwest of El Hato Del Volcan , T.S. Cochrane et al. 6327 (MO); Boquete, ca. 26 km N of David along the road to Boquete, Curatella-Byrsonima-Trachypogon savanna on old lava flow, G. Davidse & W.G. D'Arcy 10138 (MO); Boquete, eastern slope of Volcan de Chiriqui ( Baru ), WNW of Boquete. Partially cleared slopes with patches of original oak forest and mostly secondary growth, G. Davidse & W.G. D'Arcy 10170 (MO); Large old lava flow ca. 3 km NE of El Hato del Volcan at base of Volcan de Chiriqui ( Baru ), 1-3 km E of highway, G. Davidse & W.G. D'Arcy 10332 (MO); Llanos E of El Hato de Volcan , savannah and woods on lava flow, B. Hammel et al. 6811 (MO); Grassy slopes on lava flow about 16 km above town at Volcan, B. Hammel 1585 (MO); Volcan Baru , summit to llanos at base of W slope, along trail, B. Hammel et al. 6576 (MO); Lava fields near the town of Volcan, J.A. Duke 9143 (MO); Western slopes of Volcan de Chiriqui (Baru), on lava flow, S. Mori & J. Kallunki 5714 (MO); Bambito, in savanna 1 mile south, M. Partch 69-31 (MO); Alto Boquete, savanna, M. Partch 69-62 (MO); 2 km S of Boquete above the Rio Caldera near a small flood control dam. Disturbed roadside, P.M. Peterson & C.R. Annable 7349 (MO, US ); Between Rio Quebrado El Velo and Rio Caldera, W of San Ramon and NW of Boquete, gravel pit with very steep sandy slopes, P.M. Peterson & C.R. Annable 7372 (MO, US ); 1 km NW of Boquete on road towards Volcan Baru, dry roadcut in bare soil, P.M. Peterson & C.R. Annable 7376 (MO, US ); S end of Boquete, dry open slopes, P.M. Peterson & C.R. Annable 7385 (MO, US ); NW of Boquete, between Finca Lerida and San Ramon, P.M. Peterson & C.R. Annable 7371 (MO, US ); S end of Boquete, P.M. Peterson & C.R. Annable 7386 (MO, US ); Ca 1.5 mi. northeast of El Hato del Volcan, grassy plain with occasional patches of forest, S. McDaniel 10199 (MO); Foothills, vicinity of El Boquete, A.S. Hitchcock 8241 ( US ); foothills, vicinity of El Boquete, A.S. Hitchcock , 8242 ( US ); Cerro Vaca, eastern Chiriqui, in savannas, H. Pittier 5360 ( US ); Cerro Vaca, eastern Chiriqui, in savannas, H. Pittier 5362 ( US ). Cocle : hills S of El Valle de Anton , P.H. Allen 2812 (MO);vicinity of Ola, H. Pittier 5062 ( US ), H. Pittier 5042 ( US ). Veraguas : Cerro Campana, savannas S of radio tower, B. Hammel 5528 (MO).