Bromus porteri
Bromus arizonicus
nodding brome, Porter brome, Porter's brome
Arizona brome
30-100 cm, erect;
nodes (2)3-4(5), glabrous or pubescent;
internodes mostly glabrous, puberulent near the nodes.
30-90 cm tall, to 3 mm thick, erect.
glabrous or pilose, midrib of the culm leaves not abruptly narrowed just below the collar;
auricles absent;
ligules to 2.5 mm, glabrous, truncate or obtuse, erose or lacerate;
blades (3)10-25(35) cm long, 2-5(6) mm wide, flat, not glaucous, both surfaces usually glabrous, sometimes the adaxial surface pilose.
retrorsely pilose, sometimes mostly glabrous, throats sometimes with hairs;
auricles absent;
ligules 1-4 mm, usually glabrous, obtuse, erose;
blades 8-18 cm long, 3-9 mm wide, flat, sparsely pilose on both surfaces or the abaxial surfaces glabrous.
7-20 cm, open, nodding, often 1-sided;
branches slender, ascending to spreading, often recurved and flexuous.
12-25 cm, somewhat contracted or open;
lower branches shorter than 10 cm, 2-3(5) per node, initially erect to ascending, spreading at maturity, with 1-2 spikelets variously distributed.
12-38 mm, elliptic to lanceolate, terete to moderately laterally compressed, with (3)5-11(13) florets.
18-25 mm, elliptic to lanceolate, strongly laterally compressed, with 4-8 florets.
usually pubescent, rarely glabrous;
lower glumes 5-7(9) mm, usually 3-veined, sometimes 1-veined;
upper glumes 6-10 mm, 3-veined, not mucronate;
lemmas 8-14 mm, elliptic, rounded over the midvein, usually pubescent or pilose, margins often with longer hairs, backs and margins rarely glabrous, apices acute or obtuse to truncate, entire;
awns (1)2-3(3.5) mm, straight, arising less than 1.5 mm below the lemma apices;
anthers (1)2-3 mm.
subequal, smooth or scabrous;
lower glumes 8-12.5 mm, 3-veined;
upper glumes 9.5-14 mm, 7-veined, about as long as the lowest lemma;
lemmas 9.5-14 mm, lanceolate, laterally compressed, prominently 7-veined, strongly keeled at least distally, glabrous or pubescent distally or throughout, marginal hairs, if present, longer than those elsewhere, apices entire or with acute teeth shorter than 1 mm;
awns 6-13 mm, sometimes slightly geniculate;
anthers 0.4-0.5 mm.
= 14.
= 84.
Bromus porteri
Bromus arizonicus
Bromus porteri grows in montane meadows, grassy slopes, mesic steppes, forest edges, and open forest habitats, at 500-3500 m. It is found from British Columbia to Manitoba, and south to California, western Texas, and Mexico. It is closely related to B. anomalus, and has often been included in that species. It differs chiefly in its lack of auricles, and in having culm leaves with midribs that are not narrowed just below the collar.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Bromus arizonicus grows in dry, open areas and disturbed ground of the southwest, usually below 2000 m. Its range extends from California and southern Nevada into Arizona, New Mexico, and northern Mexico.
Stebbins et al. (1944) demonstrated that, like Bromus carinatus var. carinatus, B. arizonicus obtained three of its genomes from B. catharticus or a close relative, but the remaining three genomes are not homologous with those in B. carinatus, probably being derived from a species in a section other than Ceratochloa. The small anthers of B. arizonicus strongly suggest that most seed is produced by selfing.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
BC
CA
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
