Bromus japonicus Houttuyn (1772: 315)

Saarela, Jeffery M., Peterson, Paul M. & Valdés-Reyna, Jesus, 2014, A taxonomic revision of Bromus (Poaceae: Pooideae: Bromeae) in México and Central America, Phytotaxa 185 (1), pp. 1-147 : 98-101

14. Bromus japonicus Houttuyn (1772: 315) . Figs. 47 , 48 .

Bromus japonicus Thunb. in Murray (1784: 119), nom. illeg. Bromus arvensis var. japonicus (Thunb. in Murr.) Fiori (1923: 149). Serrafalcus japonicus (Thunb.) Wilmott in Babington & Wilmott (1922: 510). Type:— JAPAN. Thunberg s.n. (holotype UPS).

98 Phytotaxa 185 (1) © 2014 Magnolia Press

SAARELA ET AL.

Plants annual. Culms 17–85 cm tall, 1–2.2 mm wide at base, erect or ascending, glabrous below inflorences; nodes 3–4. Leaf sheaths densely pilose, hairs up to 1.2 mm long; auricles absent; ligules 1–2.2 mm long, glabrous, apex erose; blades 3.5–13 cm × 1–6 mm, flat, adaxial and abaxial surfaces densely pubescent with short, stiff hairs up to 0.6 mm long, margins smooth or serrulate. Panicles 3–26 cm × 6–16 cm, open, nodding, branches spreading to ascending, usually longer than spikelets, glabrous or scabrous, 1–6 spikelets per branch. Spikelets 1.8–4 cm long, 7–15-flowered, broadly oblong to ovate-lanceolate, terete to moderately laterally compressed, rachillas sometimes visible at maturity; glumes glabrous, margins sometimes hyaline, midnerves glabrous proximally, scabrous distally, apices obtuse; lower glumes 4–7 mm long, oblong to ovate, 3–5(–7)-nerved; upper glumes 5–8 mm long, ovate to elliptic, 7–9-nerved; lemmas 7–9.2 mm × 1.2–2.2 mm, ovate to elliptic, rounded over the backs, apices obtuse to truncate, often minutely bifid, the cleft to 1 mm deep, 7–9-nerved, nerves not conspicuous, backs glabrous or scabridulous, scabrules ca. 0.1 mm long, hyaline margins 0–0.5 mm widest point; awns 4.2–13 mm long, awn on lowest lemma usually shorter, arising 1.5–2.6 mm below lemma apex, straight to strongly divergent, widest at base; paleas 6–7 mm long, backs glabrous, keels ciliate, cilia 0.3–0.5 mm long; anthers 0.6–1.1 mm long; caryopses 5−6 mm long, terete in cross section to somewhat flattened. 2 n = 14 ( Venter & Spies 2008).

Distribution:—Introduced. In México B. japonicus is known from a few collections from Chihuahua, Coahuila and Jalisco ( Fig. 49 ). Beetle (1987) noted that B. japonicus has been collected in Jalisco, but is not established there. McVaugh (1983) noted that B. japonicus is present in abandoned experimental plots south of Ocotlán, Jalisco; a specimen from this area is cited below. The Chihuahua collections were made from cultivated plants. The current status of the species in México is unknown. Bromus japonicus is native to Europe. In North America, B. japonicus is distributed widely throughout the U.S.A. and in southern Canada ( Pavlick & Anderton 2007).

Ecology: — Bromus japonicus is found in disturbed sites in pastures and near cultivated fields. Elevation: 1500−2460 m.

Common Names: —Japanese chess, Japanese bromegrass, Japanese brome, spreading brome (English).

ATAXONOMIC REVISION OF BROMUS (POACEAE)

Phytotaxa 185 (1) © 2014 Magnolia Press 99

100 Phytotaxa 185 (1) © 2014 Magnolia Press

SAARELA ET AL.

Specimens Examined:― MÉXICO. Chihuahua: Rancho Exp. La Campana , Chihuahua, Jardín de observacion (cultivated), 1540 m, 14 May 1977, M. S . González-Elizondo 838 ( SD-126969 ); Rancho Experimental La Campana-Chihuahua , [28.63°N, 106.08°W], 1540 m, 5 August 1977, M. S . González E . s.n. ( ANSM); Rancho Experimental La Campana , 82 kms al norte de la Cd. de Chihuahua, 1500 m, 26 August 1978, s.c. ( MEXU- 243518 ) . Coahuila: Mpio. Arteaga, ejido La Escondida, Bosque aciculiesclerofilo, 2460 m, 21 Junio 1994, P . Moya 447 ( MEXU-1089017 , MEXU-1089018 ) . Jalisco: ca. 3 km al Sde Ocotlán por la carretera a La Barca, parcela experimental abandonada, 20.2889°N, 102.8389°W, 21 May 1978, R . Guzmán Mejía 792 ( MEXU-250562 , as B. squarrosus L.) .

Figures

FIGURE 47. Bromus japonicus. A. Glumes. B. Lemma. C. Spikelet. D. Ligule. E. Habit. F. Inflorescence. Illustration by C.T. Roché, reproduced from Barkworth et al. (2007) with permission.

FIGURE 48. Bromus japonicus. González-Elizondo 838 (SD-126969).

FIGURE 49. Geographical distribution of Bromus japonicus in México.