OregonFlora: Bromus tectorum vs. Bromus vulgaris

	Bromus tectorum	Bromus vulgaris
	cheatgrass, downy brome, downy chess	Columbia brome
Habit	Plants annual, 5–90 cm tall.	Plants perennial, 60–120 cm tall; loosely cespitose.
Culms	puberulent.	internodes glabrous; nodes (3)4–6(7), usually pilose.
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 pilose or glabrous; ligules 2–6 mm; blades 13–25(33)cm × up to 14 mm; flat; upper and lower surfaces usually glabrous, sometimes pilose.
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.	10–15 cm, usually narrow, nodding; the branches ascending to appressed.
Spikelets	10–20 mm, moderately laterally compressed, not densely crowded, 4–8 florets.	15–30 mm, elliptic to lanceolate; terete to moderately laterally compressed, with (3)4–9 florets.
Glumes	villous, pubescent, or glabrous; lower glumes 4–9 mm, 1-veined; upper glumes 7–13 mm, 3–5-veined.	glabrous or pilose; lower glumes 5–8 mm, 1(3)-veined; upper glumes 8–12 mm, 3-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.	8–15 mm, lanceolate, rounded over the back; backs sparsely hairy or glabrous; margins coarsely pubescent, sometimes glabrous; tips subulate to acute; entire, awned; lemma awns (4)6– 12 mm; straight.
Anthers	0.5–1 mm.	2–4 mm.
2n	=14.	=14.

	Bromus tectorum	Bromus vulgaris
Distribution	[WildflowerSearch map] [BONAP county map]	[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.	Forests, in shade or partial shade. 0–2400m. BW, Casc, CR, ECas, Est, Sisk, WV. CA, ID, WA; north to British Columbia, northeast to Alberta, east to WY. Native. Bromus vulgaris is a common forest grass of western Oregon and the Blue and Wallowa mountains. Its closed sheaths with spreading hairs and its long, narrow spikelets distinguish it from most other woodland grasses. Invasive Brachypodium sylvaticum has similar nodding inflorescences with long spikelets, but all the spikelets are connected directly to the inflorescence axis by very short, unbranched stalks, and the leaf sheath margins are overlapping.
Source	Flora of Oregon, volume 1, page 374 Barbara Wilson, Richard Brainerd, Nick Otting	Flora of Oregon, volume 1, page 374 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. rubens, B. secalinus, B. sitchensis, B. squarrosus, B. sterilis, B. suksdorfii, B. tectorum
Synonyms	Bromus tectorum var. glabratus, Bromus tectorum var. nudus, Bromus tectorum var. tectorum	Bromus vulgaris var. eximius, Bromus vulgaris var. robustus, Bromus vulgaris var. vulgaris
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 vulgaris

cheatgrass, downy brome, downy chess

Columbia brome

Habit

Plants annual, 5–90 cm tall.

Plants perennial, 60–120 cm tall; loosely cespitose.

Culms

puberulent.

internodes glabrous;

nodes (3)4–6(7), usually pilose.

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 pilose or glabrous;

ligules 2–6 mm;

blades 13–25(33)cm × up to 14 mm; flat; upper and lower surfaces usually glabrous, sometimes pilose.

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.

10–15 cm, usually narrow, nodding; the branches ascending to appressed.

Spikelets

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

15–30 mm, elliptic to lanceolate; terete to moderately laterally compressed, with (3)4–9 florets.

Glumes

villous, pubescent, or glabrous;

lower glumes 4–9 mm, 1-veined;

upper glumes 7–13 mm, 3–5-veined.

glabrous or pilose;

lower glumes 5–8 mm, 1(3)-veined;

upper glumes 8–12 mm, 3-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.

8–15 mm, lanceolate, rounded over the back; backs sparsely hairy or glabrous;

margins coarsely pubescent, sometimes glabrous;

tips subulate to acute; entire, awned;

lemma awns (4)6– 12 mm; straight.

Anthers

0.5–1 mm.

2–4 mm.

=14.

Bromus vulgaris

Distribution

[WildflowerSearch map]

[BONAP county map]

[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.

Forests, in shade or partial shade. 0–2400m. BW, Casc, CR, ECas, Est, Sisk, WV. CA, ID, WA; north to British Columbia, northeast to Alberta, east to WY. Native.

Bromus vulgaris is a common forest grass of western Oregon and the Blue and Wallowa mountains. Its closed sheaths with spreading hairs and its long, narrow spikelets distinguish it from most other woodland grasses. Invasive Brachypodium sylvaticum has similar nodding inflorescences with long spikelets, but all the spikelets are connected directly to the inflorescence axis by very short, unbranched stalks, and the leaf sheath margins are overlapping.

Source

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

Sibling taxa