OregonFlora: Bromus diandrus vs. Bromus ramosus

	Bromus diandrus	Bromus ramosus
	ripgut brome
Habit	Plants annual, 20–90 cm tall.
Culms	puberulent.
Leaves	sheaths softly pilose, often with retrorse or spreading hairs; blades 3.5–27 cm × 1–9 mm, pilose on both surfaces.
Inflorescences	panicles 13–25 × 2–17 cm, nodding at maturity but occasionally erect; branches 1–7 cm, stiffly erect to ascending or spreading, 1–2 spikelets.
Spikelets	25–70 mm, moderately laterally compressed, with 4–11 florets.
Glumes	smooth or scabrous; lower glumes 15– 25 mm, 1–3-veined; upper glumes 25–35 mm, 3–5-veined.
Lemmas	22–30 mm, linear-lanceolate, scabrous, 7-veined; margins hyaline; tips acuminate; bifid; teeth 3–5 mm, awned; lemma awns 30–65 mm; straight.
Anthers	0.5–1 mm.
2n	=28, 42, 56.

	Bromus diandrus	Bromus ramosus
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	Disturbed open areas, degraded grasslands. 0–1300m. Col, CR, ECas, Est, Lava, Sisk, WV. CA, ID, NV, WA; north to British Columbia, southeast to TX, south to Mexico, scattered in the eastern US; Europe. Exotic. Bromus diandrus is a common weed, typically with gracefully curved inflorescences and long lemma awns. The long awns can lodge in the mouths and digestive tracts of herbivores, causing injury. Similar B. sterilis is smaller in all its parts.
Source	Flora of Oregon, volume 1, page 370 Barbara Wilson, Richard Brainerd, Nick Otting
Sibling taxa	B. arenarius, B. briziformis, B. catharticus, B. ciliatus, B. commutatus, 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, 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, B. vulgaris
Synonyms	Bromus rigidus, Bromus rigidus var. gussonei, Bromus rigidus var. rigidus
Web links	Local floras: 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 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 ramosus

ripgut brome

Habit

Plants annual, 20–90 cm tall.

Culms

puberulent.

Leaves

sheaths softly pilose, often with retrorse or spreading hairs;

blades 3.5–27 cm × 1–9 mm, pilose on both surfaces.

Inflorescences

panicles 13–25 × 2–17 cm, nodding at maturity but occasionally erect;

branches 1–7 cm, stiffly erect to ascending or spreading, 1–2 spikelets.

Spikelets

25–70 mm, moderately laterally compressed, with 4–11 florets.

Glumes

smooth or scabrous;

lower glumes 15– 25 mm, 1–3-veined;

upper glumes 25–35 mm, 3–5-veined.

Lemmas

22–30 mm, linear-lanceolate, scabrous, 7-veined;

margins hyaline;

tips acuminate; bifid;

teeth 3–5 mm, awned;

lemma awns 30–65 mm; straight.

Anthers

0.5–1 mm.

=28, 42, 56.

Bromus ramosus

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Disturbed open areas, degraded grasslands. 0–1300m. Col, CR, ECas, Est, Lava, Sisk, WV. CA, ID, NV, WA; north to British Columbia, southeast to TX, south to Mexico, scattered in the eastern US; Europe. Exotic.

Bromus diandrus is a common weed, typically with gracefully curved inflorescences and long lemma awns. The long awns can lodge in the mouths and digestive tracts of herbivores, causing injury. Similar B. sterilis is smaller in all its parts.

Source

Flora of Oregon, volume 1, page 370
Barbara Wilson, Richard Brainerd, Nick Otting

Sibling taxa