11. Bromus frondosus (Shear) Wooton & Standley (1912: 144) . Figs. 38, 39.

Basionym: Bromus porteri var. frondosus Shear (1900: 37) . Bromopsis frondosa (Shear) Holub (1973: 167) . Type:— UNITED STATES OF AMERICA. New México: Grant Co., Mangas Springs, 19 August 1897, J.G. Smith s.n. (holotype US-81587!).

Plants perennial, not rhizomatous. Culms 54–84 cm tall, 2–4 mm wide at base, erect to spreading, glabrous below inflorescences, nodes 3–5, glabrous, occassionally with a few short hairs. Leaf sheaths sparsely to densely pilose, hairs up to 1.2 mm long; auricles absent; ligules 0.5–2 mm long, glabrous; blades up to 29 cm × 4–6 mm, flat, adaxial and abaxial surfaces usually glabrous, sometimes pubescent, hairs up to 1 mm long distally, margins serrulate. Panicles 9–13 cm × 3–6 cm, open, nodding, branches ascending to spreading, 0.5–5 cm long, shorter or longer than spikelets, scabrous, 1–4 spikelets per branch. Spikelets 1.6–3 cm long, 7–9-flowered, elliptic to lanceolate, terete to moderately laterally compressed; glumes glabrous, scabrous or minutely pubescent, hairs when present sometimes restricted to margins, margins hyaline, midnerves glabrous or scabrous; lower glumes 6–8.5 mm × 0.6–1.0 mm, lanceolate, 3-nerved, green along and between the nerves, apices acute; upper glumes 8–10 mm × 0.9–1.3 mm, oblong-ovate, 3-nerved, green along and between the nerves, apices acute or mucronate, mucros to 1 mm long; lemmas 9–12 mm × 1.5–2.5 mm, elliptic to lanceolate, rounded over the backs, apices truncate, 5–7- nerved, green along and between the nerves, backs glabrous or sparsely to densely pubescent, margins pubescent on lower third to half, hairs up to 1 mm long; awns 3.5–6 mm long, arising 0–0.5 mm below lemma apex, straight; paleas shorter than the lemmas, 9–10 mm long, backs glabrous or pubescent, keels ciliate, cilia up to 0.2 mm long; anthers 1.5–3.5 mm long; caryopses 6−8 mm long. 2 n = 14 (Wagnon 1952).

Distribution: ―Native. In México B. frondosus is known from Chihuahua, Coahuila, Durango, Sinaloa and Sonora (Fig. 40). It extends northwards to Colorado, New México and Arizona (Pavlick & Anderton 2007).

Ecology: — Bromus frondosus is found on rocky slopes and rock outcrops, roadcuts and rocky meadows; associated with Pinus cembroides, Pinus spp., Quercus, spp., Juniperus deppeana, Abies religiosa, Pseudotsuga menziesii, Cupressus arizonica, Rhamnus, Ceanothus, Arbutus, Arctostaphylos pungens, Cercocarpus Kunth in Humboldt (1824: 6), Salvia, Platanus wrightii Watson (1875: 349), Senecio and Garrya flavescens Watson (1873: 301) . Elevation: 1295–2745 m.

Common Names:— Weeping brome (English); bromo frondoso (Spanish).

Comments: ― Bromus frondosus is distinguished by its 3-nerved lower glumes.

Specimens Examined:― MÉXICO. Chihuahua: Mpio. Madera, Laguna de Babícora, Arroyo Las Varas, [29.0556°N, 106.8611°W], 2300 m, 10 September 1994, G . Quintana & E. Estrada 3556 (NY); "Rancho el peñasco" km 150 carretera Chihuahua-Cd. Juárez, [29.77°N, 107.37°W], 1720 m, 9 August 1979, M . Siqueiros 336 (MEXU-1098029); 20.3 km NE of Ignacio Zaragoza on MEX 23 , [29.75°N, 107.64°W], 2400 m, 28 September 1989, P.M . Peterson & R.M . King 8154 (CAN, US); 24.7 mi Nof San Juanito on road towards Cuauhtémoc, 28.2636°N, 107.4931°W, 2233 m, 5 September 2008, P.M . Peterson & J.M . Saarela 22028 (CAN, US); 30.2 km N of San Juanito on road to Creel, [28.26°N, 107.61°W], 2235 m, 10 September 1989, P.M . Peterson, C.R . Annable & Y . Herrera-Arrieta 8002 (CAN, MO, US); 34 mi Wof Balleza on road towards Guachochic, [27.12°N, 106.79°W], 2500 m, 29 October 1995, P.M . Peterson, M.B . Knowles, C.H . Dietrich & S.M . Braxton 13539 (US); 8 mi Nof Santo Tomás, 28.81°N, 107.5667°W, 2010 m, 8 October 1953, J.R . Reeder & C.G . Reeder 2625 (US-2473583); ca. 23 (air) mi ENE of Villa Ahumada in NW canyon of Sierra de la Alcaparra NE of Rancho El Palmar, 30.6667°N, 106.1°W, 6000 ft [1828 m], 12 September 1973, J . Henrickson 12864 (MEXU-1052580, RSA-POM-665758); Colonia Cumbres de Majalca, 33.8 km Wof MEX 45, Nof Chihuahua City, [28.8°N, 106.46°W], 2190 m, 7 September 1989, P.M . Peterson, C.R . Annable & Y . Herrera-Arrieta 7969 (CAN, US); km 11 entre San Bueneventura y El Carmen, carratera Nuevo Casas Grandes, 29.84°N, 107.47°W, 1600 m, 19 September 1955, E . Hernández X. & V . Mathus L . N-1941 (GH); km 18 de San José Babícora a Santa Ana Babícora, 2200 m, 30 October 1954, E . Hernández X. & C . Tapia J . N-438 (GH); Majalca (Pilares), [28.68°N, 106.11°W], 12 September 1939, L.H . Harvey 1485 (GH, mixed sheet with B. carinatus var. carinatus); Majalca, [28.73°N, 106.1°W], 18–20 September 1935, H . LeSueur 30 (GH); Majalca, NW of Chihuahua, [28.73°N, 106.1°W], 2050–2100 m, 29 September 1934, F.W . Pennell 19299 (GH); near Colonia Garcia, [29.97°N, 108.35°W], 7500 ft [2286 m], 14 September 1899, C.H.T . Townsend & C.M . Barber (MSC-229571); Río Negro, 28 August 1937, H . LeSueur 0213 (GH); San Ysidro, SW of Barranca, [28.5667°N, 107.45°W], 13 May 1929, Y . Mexia 2524 (MICH-1119284, NY, RSA-POM-364164); Sánchez, [31.77°N, 107.64°W], 8000 ft [2438 m], 12 October 1910, A.S . Hitchcock s.n. (MEXU); Santa Clara Canyon, [29.72°N, 107.08°W], 18 August 1936, H . LeSueur 0123 (GH); Sierra de los Órganos, 28.25°N, 104.75°W, 9 August 1937, H . LeSueur 211 (GH, mixed sheet with B. carinatus var. marginatus), US-1721654 ); Sierra Madre Mts., Colonia Juárez, [30.3°N, 108.06°W], 6000 ft [1829 m], 12 September 1903, M.E . Jones s.n. (RSA-POM-112405); Sierra Madre Mts., Meadow Valley, [30.3°N, 108.06°W], 7000 ft [2134 m], 17 September 1903, M.E . Jones s.n. (RSA-POM-112403); Sierra Madre Occidental, 12.1 mi W of San Juanito on road towards Baquiriachic, 27.9567°N, 107.76°W, 2530 m, 5 October 2000, P.M . Peterson & J . Cayouette 15358 (CAN, US); Sierra Madre Occidental, 16.7 mi Wof Baquiriachic on Hwy. 16 towards Maycoba, 28.3543°N, 108.28°W, 2000 m, 4 October 2000, P.M . Peterson & J . Cayouette 15353 (CAN, MO, US); Sierra Madre Occidental, 20.3 mi Sof Creel on road towards Rocheachic, 27.5387°N, 107.51°W, 2510 m, 5 October 2000, P.M . Peterson & J . Cayouette 15368 (CAN, US); Sierra Madres near Colonia Garcia, [29.97°N, 108.34°W], 7500 ft [2286 m], 14 September 1899, C.H.T . Townsend & C.M . Barber 327 (F-103052, MEXU-5764, MICH-1119280, MSC-229571, NY, 2 sheets); SW slope of Sierra de la Ranchería (on Rancho Candelaria), 31.0167°N, 106.35°W, 1500–2180 m, 29 October 1972, T.L . Wendt, F . Chiang & M.C . Johnston 9949 (MEXU-729813, NY); 19.6 km Wof Balleza and 74.2 km Eof Guachochi, [26.9453°N, 106.4783°W], 2120 m, 18 September 1991, P.M . Peterson, C.R . Annable & J . Valdés-Reyna 10753 (US); along dirt road to Cuesta Blanca in Sierra Brena SW of Colonia Juárez, 2256 m, 21 September 1992, K.W . Allred, T . Columbus & J . Valdés-Reyna 5727 (ANSM); 19.6 km Wof Balleza and 74.2 km Eof Guachochi, 2120 m, 18 September 1991, P.M . Peterson, C.R . Annable & J . Valdés-Reyna 10753 (US); Boycoyna, La Junta, Alrededores, 13 September 2003, R . Bye, M . Mendoza, G . Morales, J . Rodríguez & M. Hilerio 32463 (US-3589121); Creel, Chih. 125 Creel km 90, Sitio 125 km 96.2, La Mesa de Yeguachi, 27°47.155’N, 107°38.611’W, 2248 m, 13 September 2003, R . Bye, M . Mendoza, G . Morales, J . Rodríguez & M. Hilerio 32541 (US-3589119); Guachochi, Norogachi, Planicie, 16 September 2003, R . Bye, M . Mendoza, G . Morales, J . Rodríguez & M. Hilerio 32771 (US-3589146). Coahuila: Mpio. Saltillo, area montañosa del Cañón " San Lorenzo", 25.3167°N, 101.95°W, 2000 m, M.G . Villaseñor s.n. (ANSM); Sierra del Carmen, 28.9867°N, 102.9739°W, 2432 m, 30 August 1997, S . Wood, C . Crider & D. Doan-Crider s.n. (ANSM); Maderas del Carmen, 2.0 mi from Campo Uno, up the road towards the summit, 29.0062°N, 102.6054°W, 2571 m, 22 September 2007, P.M . Peterson, J.M . Saarela, S . Lara Contreras & J . Reyna Álvarez 21029 (CAN, MO, US); Sierra El Jardín, 29.0832°N, 102.6371°W, 2100 m, 3 September 2006, P.M . Peterson & S . Lara-Contreras 19941 (CAN, US). Durango: Sierra Madre Occidental, 11 mi NE of Ojito de Camillones on road towards Papasquiaro, 25.0912°N, 106.136°W, 2580 m, 12 October 2000, P.M . Peterson, J . Cayouette & M.S . González-Elizondo 15436 (US); Sierra Madre Occidental, Wof Ciudad Durango, 6 mi Wof El Salto, 23.7418°N, 105.452°W, 2745 m, 27 August 1958, J.R . Reeder & C.G . Reeder 3123 (US-2473577); 30 km Wof Durango on Hwy. 40, just Eof Rio Chico crossing, 2200 m, 29 September 1988, P.M . Peterson & C.R . Annable 6007 (US). Sinaloa: loop of the Río de Bavispe, NE Sonora, Cerro del Capulín, NW of Aribabi, 30.1°N, 109.083°W, 1875 m, 4 September 1939, L.H . Harvey 1693 (US-1762717); Morelos, 30.8167°N, 109.2167°W, 15 September 1947, J . Vera-Santos 1939 (US-2079260); region of the Río de Bavispe, NE Sonora, El Bilito, NE of El Tigre, 30.61°N, 109.17°W, 1890 m, 12 October 1941, J . Vera-Santos 2128 (US-1938696). Sonora: Arroyo Hondo, 11.5 km Eof El Kipor, 4 km Wof Chihuahua border on Son., 28.4417°N, 108.78°W, 1460 m, 11 September 1996, T.R . Van Devender, A.L. Reina G., G. Ferguson & L. Coyote 96-563 (ARIZ-332596, RSA-POM-610275); Cerro El Capulín, NW of Aribabi, [29.91°N, 109.99°W], 1875 m, 4 November 1939, L.H . Harvey 1693 (MICH-1119279); El Bilito, NE of El Tigre, [30.59°N, 109.22°W], 6200 ft [1890 m], 12 October 1941, J . Vera Santos 2128 (MICH-1119213) & 2136 (NY); El Picacho del Pilar, 7400 ft [2255 m], 13 October 1941, J . Vera Santos 2167 (MICH-1119124); El Puerto del Cumarito, Sierra de la Cabellera, [30.92°N, 109.11°W], 5400 ft [1646 m], 6 October 1941, J . Vera Santos 2079 (MICH-1119282, NY); El Rancho de Robles, NE of El Tigre, [30.76°N, 109.18°W], 6000 ft [1829 m], 2–13 September 1941, J. Vera Santos 1939 (ARIZ-124777, MICH-1119278, MEXU-537473, NY, US-1938676); La Matancita, 1 mi Wof El Tigre, [30.76°N, 109.18°W], 4250 ft [1295 m], 30 August 1941, J. Vera Santos 1915 (ARIZ-124955, MICH-1119277, MEXU-537476, NY, US-1938674); Morelos, 15 September 1947, J. Vera Santos 1915 (MICH-119276); Nof Cananea Ejido José María Morelos, [30.98°N, 110.3°W], 25 September 1981, A.A. Beetle M-7869 (ARIZ-234251, MEXU, MO); region of the Río de Bavispe, NE Sonora, El Puerto del Cumarito, Sierra de la Cabellera, 30.0333°N, 109.3333°W, 1646 m, 6 October 1941, J. Vera-Santos 2079 (US-2463582, US-1938690); Sierra Madre Occidental, 1.7 mi Wof Maycoba on Hwy. 16 towards Yécora, 28.4065°N, 108.68°W, 1720 m, 4 October 2000, P.M. Peterson & J. Cayouette 15351 (US); Sierra Madre Occidental, 1.8 mi Wof Yécora on Hwy. 16 towards Hermosillo, 28.3583°N, 108.95°W, 1860 m, 3 October 2000, P.M. Peterson & J. Cayouette 15315, 15317 (CAN, MO, US); Sierra Madre Occidental, 12.3 mi Wof Yécora on Hwy. 16 towards Hermosillo, 28.3772°N, 109.05°W, 1810 m, 3 October 2000, P.M. Peterson & J. Cayouette 15305 (US); Sierra Madre Occidental, 16 mi Wof Maycoba on Hwy. 16 towards Yécora, 28.4002°N, 108.8°W, 1520 m, 4 October 2000, P.M. Peterson & J. Cayouette 15346 (US).