Bromus secalinus Linnaeus (1753: 76)

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 : 128-129

21. Bromus secalinus Linnaeus (1753: 76) . Fig. 67 .

Bromus mollis var. secalinus (L.) Hudson (1778: 49). Avena secalina (L.) Salisbury (1796: 22). Serrafalcus secalinus (L.) Babington (1843: 374). Forasaccus secalinus (L.) Bubani (1901: 388). Type:—EUROPE. habitat in Europae agris secalinis arenosis, Anon. (neotype LINN-93.1!, designated by Smith 1985: 498).

Bromus submuticus Steudel (1854: 351) . Type:— UNITED STATES OF AMERICA. Missouri: St. Louis, 1838, N. Riehl s.n. (isotype US-865472 ! fragm.).

Plants annual. Culms 23–130 cm tall, 1–5(–7) mm wide at base, smooth; nodes 3–5, finely to densely retrorsely pubescent, hairs 0.1–0.4 mm long. Leaf sheaths glabrous or sparsely pilose, hairs soft, 0.5–0.6 mm long; auricles absent; ligules 1.7–2.8 mm long, glabrous, apex erose; blades 8–28.5 cm × 2–9 mm, flat, abaxial surface pilose, hairs up to 1.5(–2) mm long, soft and wavy, adaxial surface glabrous with occasional hairs up to 0.5 mm long, margins smooth. Panicles 11–22 cm × 2–9 cm, open, branches stiffly erect, sometimes secund, one or more lower branches usually longer than spikelet, smooth to scabrous, 1–3 spikelets per branch. Spikelets 1–2 cm long, 5–12- flowered, ovate-lanceolate, terete to slightly compressed, rachilla zigzagged and visible at maturity; glumes glabrous or scabrous, margins serrulate, midnerves glabrous, occasionally scabrous distally; lower glumes 3.6–4.9 mm long, oblong to ovate, 3–5(–7)-nerved; upper glumes 4.2–6.1 mm long, ovate to elliptic, 7–nerved, sometimes mucronate, mucros 0.2–0.6 mm long; lemmas 6–7.7 mm × 1.6–3 mm, obovate-lanceolate, apex entire or minutely bifid, the cleft 0.1–0.2 mm deep, 7–9-nerved, nerves not conspicuous, backs glabrous and shiny, occasionally scabrous distally, margins dinstinctly inrolled in fruit; awns 1–6.5 mm long, occasionally reduced to mucro or absent, arising 0.5–0.7 mm below lemma apex, usually straight, occasionally twisted once near base, widest at base; paleas ± equal in length to lemmas, apex usually visible at lemma summit, backs glabrous, keels ciliate, cilia up to 0.3 mm long; anthers 1–1.3 mm long; caryopses 6−7 mm long, U- or V-shaped, margins strongly infolded in cross section. 2 n = 28.

Distribution: —Introduced. Bromus secalinus is known in México from two collections from Veracruz ( Fig. 68 ); Beetle (1987) noted that the species is not established in Veracruz. Its current status in México is unknown. Bromus secalinus is native to Europe. In North America north of México it occurs throughout the U.S.A. and southern Canada ( Pavlick & Anderton 2007).

128 Phytotaxa 185 (1) © 2014 Magnolia Press

SAARELA ET AL.

Ecology:— Waste places and fields. Elevation: 2100–2135 m . Common Names: —cheat, cheat chess, cheatgrass, chess, chess brome, ryebrome, ryebrome (English). Specimens Examined:— MÉXICO. Veracruz: La Joya, 19.56667°N, 96.5°W, 2100 m, 9 September 1980 ,

M.T. Mejía Saulés M-212 (ARIZ-233857, MEXU-1098058); Mpio. Rafael Ramirez, Toxtlacuayan, 2135 m,

19.6167°N, 97.07°W, 16 September 1982, T . Mejía S. 949 (MEXU).

Figures

FIGURE 67. Bromus secalinus. A. Spikelet. B. Caryopsis. C. Lemmas. D. Habit. E. Inflorescence. Illustration by C.T. Roché, reproduced from Barkworth et al. (2007) with permission.

FIGURE 68. Geographical distribution of Bromus secalinus in México.