OregonFlora: Taeniatherum caput-medusae

	Taeniatherum caput-medusae
	medusahead
Habit	Plants annual, (5)10–55(70)cm tall, tufted.
Culms	erect to decumbent.
Leaves	sheaths glabrous; blades flat to involute, 0.5–2.5 mm wide, glabrous or scabrous.
Inflorescences	terminal spikes 1.2–6 cm; spikelets 2(4) per node.
Spikelets	6–45 mm, with 2(3) florets.
Glumes	awn-like; erect to reflexed; (5)7–28 mm, 1-veined, scabrous with a few scattered hairs.
Caryopses	4–5.2 mm.
Lemmas	5.5–8 mm, 5-veined, glabrous or scabrous; tips awned; lemma awns divergent; straight when young but often becoming twisted; (20)30–110 mm, arising from the lemma apex; the longest longer than the inflorescence axis.
Anthers	0.8–1 mm.
2n	=14.

	Taeniatherum caput-medusae
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	Disturbed areas, felds, dry roadsides, degraded sage steppe. 0–1900m. All ecoregions except BR. CA, ID, NV, WA; north to British Columbia, southeast to UT; Australia, Eurasia. Exotic. Taeniatherum caput-medusae has long, twisted awns that are longer than the inflorescence axis. It may be confused with Elymus elymoides, a long-awned, perennial bunchgrass with an inflorescence axis that disarticulates when mature. This grass is an aggressive invader of grasslands and shrub steppe in the arid west. It forms a dense thatch that is slow to decompose and forms monocultures that exclude both native and introduced plants, including other invasive annual grasses such as Bromus tectorum. Its forage value is limited due to its low stature and its long, irritating awns.
Source	Flora of Oregon, volume 1, page 483 Barbara Wilson, Richard Brainerd, Nick Otting
Synonyms	Elymus caput-medusae
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

Taeniatherum caput-medusae

medusahead

Habit

Plants annual, (5)10–55(70)cm tall, tufted.

Culms

erect to decumbent.

Leaves

sheaths glabrous;

blades flat to involute, 0.5–2.5 mm wide, glabrous or scabrous.

Inflorescences

terminal spikes 1.2–6 cm;

spikelets 2(4) per node.

Spikelets

6–45 mm, with 2(3) florets.

Glumes

awn-like; erect to reflexed; (5)7–28 mm, 1-veined, scabrous with a few scattered hairs.

Caryopses

4–5.2 mm.

Lemmas

5.5–8 mm, 5-veined, glabrous or scabrous;

tips awned;

lemma awns divergent; straight when young but often becoming twisted; (20)30–110 mm, arising from the lemma apex; the longest longer than the inflorescence axis.

Anthers

0.8–1 mm.

=14.

Taeniatherum caput-medusae

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Disturbed areas, felds, dry roadsides, degraded sage steppe. 0–1900m. All ecoregions except BR. CA, ID, NV, WA; north to British Columbia, southeast to UT; Australia, Eurasia. Exotic.

Taeniatherum caput-medusae has long, twisted awns that are longer than the inflorescence axis. It may be confused with Elymus elymoides, a long-awned, perennial bunchgrass with an inflorescence axis that disarticulates when mature. This grass is an aggressive invader of grasslands and shrub steppe in the arid west. It forms a dense thatch that is slow to decompose and forms monocultures that exclude both native and introduced plants, including other invasive annual grasses such as Bromus tectorum. Its forage value is limited due to its low stature and its long, irritating awns.

Source

Flora of Oregon, volume 1, page 483
Barbara Wilson, Richard Brainerd, Nick Otting

Synonyms

Elymus caput-medusae

Web links