OregonFlora: Bromus tectorum vs. Bromus pacificus

	Bromus tectorum	Bromus pacificus
	cheatgrass, downy brome, downy chess	Pacific brome
Habit	Plants annual, 5–90 cm tall.	Plants perennial, 60–170 cm tall; cespitose.
Culms	puberulent.	internodes glabrous, sometimes pubescent near the nodes; nodes (5)6–8, pubescent.
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; ligules 2–4 mm; blades 20–35(37) cm × 6–16 mm wide; flat; lower surfaces glabrous; upper surfaces 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.	10–25 cm; open; more or less erect; branches spreading to drooping.
Spikelets	10–20 mm, moderately laterally compressed, not densely crowded, 4–8 florets.	20–30 mm, elliptic to lanceolate; terete to moderately laterally compressed, with (4)6–10 florets.
Glumes	villous, pubescent, or glabrous; lower glumes 4–9 mm, 1-veined; upper glumes 7–13 mm, 3–5-veined.	pubescent; lower glumes 6–8.5 mm, 1(3)-veined; upper glumes 8–11.5 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.	10–12 mm, lanceolate, rounded over the back; backs pubescent; margins more densely pubescent; tips acute; entire; lemma awns 3.5–7 mm; straight.
Anthers	0.5–1 mm.	2–4 mm.
2n	=14.

	Bromus tectorum	Bromus pacificus
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.	Moist thickets and forest edges along the coast. 0–1700m. Est. North to AK. Native. Bromus pacificus is a tall brome of coastal thickets, with widely spreading inflorescence branches and broad leaves. It most closely resembles B. sitchensis, which has glabrous or scabrous glumes. Bromus pacificus is often reported from inland sites west of the Cascades, but none of these reports have been confirmed and they are likely B. sitchensis.
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. rubens, 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
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, OR, WA Local Web sites: 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 pacificus

cheatgrass, downy brome, downy chess

Pacific brome

Habit

Plants annual, 5–90 cm tall.

Plants perennial, 60–170 cm tall; cespitose.

Culms

puberulent.

internodes glabrous, sometimes pubescent near the nodes;

nodes (5)6–8, pubescent.

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;

ligules 2–4 mm;

blades 20–35(37) cm × 6–16 mm wide; flat;

lower surfaces glabrous;

upper surfaces 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.

10–25 cm; open; more or less erect;

branches spreading to drooping.

Spikelets

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

20–30 mm, elliptic to lanceolate; terete to moderately laterally compressed, with (4)6–10 florets.

Glumes

villous, pubescent, or glabrous;

lower glumes 4–9 mm, 1-veined;

upper glumes 7–13 mm, 3–5-veined.

pubescent;

lower glumes 6–8.5 mm, 1(3)-veined;

upper glumes 8–11.5 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.

10–12 mm, lanceolate, rounded over the back; backs pubescent;

margins more densely pubescent;

tips acute; entire;

lemma awns 3.5–7 mm; straight.

Anthers

0.5–1 mm.

2–4 mm.

=14.

Bromus pacificus

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.

Moist thickets and forest edges along the coast. 0–1700m. Est. North to AK. Native.

Bromus pacificus is a tall brome of coastal thickets, with widely spreading inflorescence branches and broad leaves. It most closely resembles B. sitchensis, which has glabrous or scabrous glumes. Bromus pacificus is often reported from inland sites west of the Cascades, but none of these reports have been confirmed and they are likely B. sitchensis.

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