OregonFlora: Bromus tectorum vs. Bromus rubens

	Bromus tectorum	Bromus rubens
	cheatgrass, downy brome, downy chess	foxtail chess, red brome
Habit	Plants annual, 5–90 cm tall.	Plants annual, 10–40 cm tall.
Culms	puberulent.	often puberulent.
Leaves	sheaths densely and softly retrorsely pubescent to pilose; upper sheaths sometimes glabrous; blades 1–16 cm × 1–6 mm, softly hairy on both surfaces.	sheaths softly pubescent to pilose; blades 1–15 cm × 1–5 mm, pubescent on both surfaces.
Inflorescences	5–20 × 3–8 cm; open, nodding; branches 1–4 cm, drooping, 1-sided and longer than the spikelets, usually at least 1 branch with 4–8 spikelets.	2–10 × 2–5 cm; erect; dense, often reddish brown; branches 0.1–1 cm, ascending, never drooping, not readily visible, 1–2 spikelets.
Spikelets	10–20 mm, moderately laterally compressed, not densely crowded, 4–8 florets.	18–25 mm; much longer than the panicle branches, densely crowded, subsessile, moderately laterally compressed, with 4–8 reddish florets.
Glumes	villous, pubescent, or glabrous; lower glumes 4–9 mm, 1-veined; upper glumes 7–13 mm, 3–5-veined.	pilose; lower glumes 5–8 mm, 1(3)-veined; upper glumes 8–12 mm, 3–5-veined.
Lemmas	9–12 mm, lanceolate, glabrous or pubescent to pilose, 5–7-veined; tips acuminate; hyaline; bifid, with teeth 0.8–2(3)mm, awned; lemma awns 10–18 mm; straight.	10–15 mm, linear-lanceolate, pubescent to pilose, 7-veined; margins hyaline; tips acuminate, with teeth 1–4 mm, awned; lemma awns 8–20 mm; straight.
Anthers	0.5–1 mm.	0.5– 1 mm.
2n	=14.	=14, 28.

	Bromus tectorum	Bromus rubens
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	Disturbed areas, sagebrush steppe, degraded grasslands, roadsides. 0–2400 m. BR, BW, Casc, Col, CR, ECas, Lava, Owy, Sisk, WV. CA, ID, NV, WA; throughout North America; worldwide. Exotic. Bromus tectorum is a relatively short grass with drooping inflorescences. Similar B. sterilis and B. diandrus have longer glumes, lemmas, and awns, and spikelets that hang down at a shallower angle than those of B. tectorum. The introduction of B. tectorum to shrub steppe habitats during a time of massive overgrazing in the late 1800s has made restoration of native plant communities difficult or impossible, even where grazing no longer occurs. Fast-growing B. tectorum seedlings outcompete slower growing native grass seedlings for water in drying soils. At maturity, the awns make B. tectorum unpalatable to livestock.	Disturbed places, bare droughty soils. 0–1400m. BR, Casc, Col, Est, Lava, Owy, Sisk, WV. CA, ID, NV, WA; east to CO and TX; MA, NY; Europe. Exotic. Similar B. diandrus and B. sterilis usually have nodding inflorescences with the spikelets angling down and much more open inflorescences. Bromus madritensis is very similar to B. rubens with which it is sometimes considered conspecific. Bromus madritensis was collected once on ballast in Portland in 1912 and apparently did not persist. It has a somewhat looser inflorescence with longer, exposed, erect panicle branches.
Source	Flora of Oregon, volume 1, page 374 Barbara Wilson, Richard Brainerd, Nick Otting	Flora of Oregon, volume 1, page 372 Barbara Wilson, Richard Brainerd, Nick Otting
Sibling taxa	B. arenarius, B. briziformis, B. catharticus, B. ciliatus, B. commutatus, B. diandrus, B. hordeaceus, B. inermis, B. japonicus, B. laevipes, B. madritensis, B. orcuttianus, B. pacificus, B. rubens, B. secalinus, B. sitchensis, B. squarrosus, B. sterilis, B. suksdorfii, B. vulgaris	B. arenarius, B. briziformis, B. catharticus, B. ciliatus, B. commutatus, B. diandrus, B. hordeaceus, B. inermis, B. japonicus, B. laevipes, B. madritensis, B. orcuttianus, B. pacificus, B. secalinus, B. sitchensis, B. squarrosus, B. sterilis, B. suksdorfii, B. tectorum, B. vulgaris
Synonyms	Bromus tectorum var. glabratus, Bromus tectorum var. nudus, Bromus tectorum var. tectorum	Bromus madritensis ssp. rubens
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Bromus rubens

cheatgrass, downy brome, downy chess

foxtail chess, red brome

Habit

Plants annual, 5–90 cm tall.

Plants annual, 10–40 cm tall.

Culms

puberulent.

often puberulent.

Leaves

sheaths densely and softly retrorsely pubescent to pilose; upper sheaths sometimes glabrous;

blades 1–16 cm × 1–6 mm, softly hairy on both surfaces.

sheaths softly pubescent to pilose;

blades 1–15 cm × 1–5 mm, pubescent on both surfaces.

Inflorescences

5–20 × 3–8 cm; open, nodding;

branches 1–4 cm, drooping, 1-sided and longer than the spikelets, usually at least 1 branch with 4–8 spikelets.

2–10 × 2–5 cm; erect; dense, often reddish brown;

branches 0.1–1 cm, ascending, never drooping, not readily visible, 1–2 spikelets.

Spikelets

10–20 mm, moderately laterally compressed, not densely crowded, 4–8 florets.

18–25 mm; much longer than the panicle branches, densely crowded, subsessile, moderately laterally compressed, with 4–8 reddish florets.

Glumes

villous, pubescent, or glabrous;

lower glumes 4–9 mm, 1-veined;

upper glumes 7–13 mm, 3–5-veined.

pilose;

lower glumes 5–8 mm, 1(3)-veined;

upper glumes 8–12 mm, 3–5-veined.

Lemmas

9–12 mm, lanceolate, glabrous or pubescent to pilose, 5–7-veined;

tips acuminate; hyaline; bifid, with teeth 0.8–2(3)mm, awned;

lemma awns 10–18 mm; straight.

10–15 mm, linear-lanceolate, pubescent to pilose, 7-veined;

margins hyaline;

tips acuminate, with teeth 1–4 mm, awned;

lemma awns 8–20 mm; straight.

Anthers

0.5–1 mm.

0.5– 1 mm.

=14.

=14, 28.

Bromus rubens

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Disturbed areas, sagebrush steppe, degraded grasslands, roadsides. 0–2400 m. BR, BW, Casc, Col, CR, ECas, Lava, Owy, Sisk, WV. CA, ID, NV, WA; throughout North America; worldwide. Exotic.

Bromus tectorum is a relatively short grass with drooping inflorescences. Similar B. sterilis and B. diandrus have longer glumes, lemmas, and awns, and spikelets that hang down at a shallower angle than those of B. tectorum. The introduction of B. tectorum to shrub steppe habitats during a time of massive overgrazing in the late 1800s has made restoration of native plant communities difficult or impossible, even where grazing no longer occurs. Fast-growing B. tectorum seedlings outcompete slower growing native grass seedlings for water in drying soils. At maturity, the awns make B. tectorum unpalatable to livestock.

Disturbed places, bare droughty soils. 0–1400m. BR, Casc, Col, Est, Lava, Owy, Sisk, WV. CA, ID, NV, WA; east to CO and TX; MA, NY; Europe. Exotic.

Similar B. diandrus and B. sterilis usually have nodding inflorescences with the spikelets angling down and much more open inflorescences. Bromus madritensis is very similar to B. rubens with which it is sometimes considered conspecific. Bromus madritensis was collected once on ballast in Portland in 1912 and apparently did not persist. It has a somewhat looser inflorescence with longer, exposed, erect panicle branches.

Source

Flora of Oregon, volume 1, page 374
Barbara Wilson, Richard Brainerd, Nick Otting

Flora of Oregon, volume 1, page 372
Barbara Wilson, Richard Brainerd, Nick Otting

Sibling taxa