OregonFlora: Elymus multisetus vs. Elymus

	Elymus multisetus	Elymus
	big squirreltail	wildrye
Habit	Plants perennial, 15–65 cm tall; cespitose.	Plants perennial; cespitose, rhizomatous, or stoloniferous.
Culms	erect to ascending.
Leaves	sheaths glabrous or white-villous; blades 1.5–4 mm wide; upper surfaces scabrous or hairy.	usually evenly distributed but sometimes mainly basal; sheaths open for most of their length; auricles often present; ligules membranous, often ciliolate; blades usually flat but sometimes folded or involute.
Inflorescences	5–20 cm; erect, sometimes partially enclosed in the sheath of the uppermost leaf, 2 spikelets per node or rarely 3–4 at some nodes; internodes 3–5(8)mm; disarticulation initially at the rachis nodes; later beneath each floret.	terminal spikes with 1–3(5) spikelets per node; internodes 1.5–26 mm.
Spikelets	10–15 mm, divergent, 2–4 florets; lowest florets sterile and glume-like in 1 or both spikelets at each node.	usually appressed to ascending but sometimes strongly divergent, 1–11 florets; the distal florets often reduced; the lowest florets usually bisexual but in some species sterile and glume-like; disarticulation usually above the glumes and beneath the florets but sometimes also below the glumes or in the inflorescence axis.
Glumes	(10)30–100 mm including the awns; the bases hard and glabrous; glume bodies about (2)5–10 × 1–2 mm, setaceous, 2–3-veined; margins firm; glume awns (8)25–90 mm; each split above the base into 3–9 unequal divisions, scabrous, flexuous to outcurving from near the bases at maturity.	usually 2 and subequal, usually linear-lanceolate to linear but sometimes bristle-like or oblanceolate to obovate; (0)1–7-veined, sometimes keeled over 1 vein, sometimes awned.
Caryopses		with densely hairy tips.
Lemmas	fertile lemmas 8–10 mm; smooth or scabrous near the tips, 2 lateral veins extending into bristles to 10 mm; lemma awns (10)20– 110 × 0.2 mm at the base, divergent to arching.	linear-lanceolate, faintly 5(7)-veined; tips acute or sometimes toothed; teeth 0.2 mm or extended as bristles to 10 mm, often awned; lemma awns terminal or from the sinus between the teeth; straight or curving and divergent, not bent.
Anthers	1–2 mm.	3.
Paleas		keels scabrous or ciliate; at least in part.
2n	=28.

	Elymus multisetus	Elymus
Distribution	[WildflowerSearch map] [BONAP county map]	[BONAP county map]
Discussion	Dry, often rocky grasslands and savannas. 50–2000m. BR, Col, ECas, Lava, Sisk, WV. CA, ID, NV, WA; southeast to CO, south to Mexico. Native. Elymus multisetus has inflorescences that fall apart at maturity and glumes that are divided into three to nine widely spreading awns. Very similar E. elymoides has glumes that are entire or unevenly split into two to three parts. Determining how much the glumes are split is complicated by the presence of glumelike sterile lemmas in both E. multisetus and some E. elymoides subspecies. Elymus multisetus glumes are divided above the base. If the glumes appear to be divided to the base, the plant is more likely to be E. elymoides.	Northern temperate regions. Approximately 150 species; 12 species treated in Flora. Some species formerly treated in Elymus have been moved to Leymus, Pascopyrum, Pseudoroegneria, and Thinopyrum. Species now treated as members of Elymus include all the species formerly treated in Sitanion and some of those from Agropyron. See discussion under Agropyron. North Asian Elymus ciliaris and E. tsukushiensis were collected in Portland 1899–1903 but have not persisted. Both have one spikelet per node, lemmas with awns curving outwards at maturity and widest leaves to 10 mm wide when flat. Reports of E. caninus from Oregon are based on misidentifications of these specimens. Elymus caninus can be distinguished from all our other Elymus species by the hairy inner surface of its glumes. When keying Elymus, measurements of spikes include the awns. Measurements of spikelets, glumes, and lemmas do not include the awns (unless specified). Rachis internodes are measured in the middle of the spike. Glume widths of lanceolate to linear glumes are measured at the widest point. Glume widths of linear to bristle-like glumes are measured about 5 mm above the base of the glumes.
Source	Flora of Oregon, volume 1, page 401 Barbara Wilson, Richard Brainerd, Nick Otting	Flora of Oregon, volume 1, page 397–403 Barbara Wilson, Richard Brainerd, Nick Otting
Sibling taxa	E. canadensis, E. ciliaris, E. elymoides, E. glaucus, E. hirsutus, E. lanceolatus, E. repens, E. trachycaulus, E. tsukushiensis, E. violaceus, E. wawawaiensis
Subordinate taxa		E. canadensis, E. ciliaris, E. elymoides, E. glaucus, E. hirsutus, E. lanceolatus, E. multisetus, E. repens, E. trachycaulus, E. tsukushiensis, E. violaceus, E. wawawaiensis
Synonyms	Sitanion jubatum
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 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

Elymus

big squirreltail

wildrye

Habit

Plants perennial, 15–65 cm tall; cespitose.

Plants perennial; cespitose, rhizomatous, or stoloniferous.

Culms

erect to ascending.

Leaves

sheaths glabrous or white-villous;

blades 1.5–4 mm wide;

upper surfaces scabrous or hairy.

usually evenly distributed but sometimes mainly basal;

sheaths open for most of their length;

auricles often present;

ligules membranous, often ciliolate;

blades usually flat but sometimes folded or involute.

Inflorescences

5–20 cm; erect, sometimes partially enclosed in the sheath of the uppermost leaf, 2 spikelets per node or rarely 3–4 at some nodes;

internodes 3–5(8)mm;

disarticulation initially at the rachis nodes; later beneath each floret.

terminal spikes with 1–3(5) spikelets per node;

internodes 1.5–26 mm.

Spikelets

10–15 mm, divergent, 2–4 florets; lowest florets sterile and glume-like in 1 or both spikelets at each node.

usually appressed to ascending but sometimes strongly divergent, 1–11 florets; the distal florets often reduced; the lowest florets usually bisexual but in some species sterile and glume-like;

disarticulation usually above the glumes and beneath the florets but sometimes also below the glumes or in the inflorescence axis.

Glumes

(10)30–100 mm including the awns; the bases hard and glabrous;

glume bodies about (2)5–10 × 1–2 mm, setaceous, 2–3-veined;

margins firm;

glume awns (8)25–90 mm; each split above the base into 3–9 unequal divisions, scabrous, flexuous to outcurving from near the bases at maturity.

usually 2 and subequal, usually linear-lanceolate to linear but sometimes bristle-like or oblanceolate to obovate; (0)1–7-veined, sometimes keeled over 1 vein, sometimes awned.

Caryopses

with densely hairy tips.

Lemmas

fertile lemmas 8–10 mm; smooth or scabrous near the tips, 2 lateral veins extending into bristles to 10 mm;

lemma awns (10)20– 110 × 0.2 mm at the base, divergent to arching.

linear-lanceolate, faintly 5(7)-veined;

tips acute or sometimes toothed;

teeth 0.2 mm or extended as bristles to 10 mm, often awned;

lemma awns terminal or from the sinus between the teeth; straight or curving and divergent, not bent.

Anthers

1–2 mm.

Paleas

keels scabrous or ciliate; at least in part.

=28.

Elymus

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Dry, often rocky grasslands and savannas. 50–2000m. BR, Col, ECas, Lava, Sisk, WV. CA, ID, NV, WA; southeast to CO, south to Mexico. Native.

Elymus multisetus has inflorescences that fall apart at maturity and glumes that are divided into three to nine widely spreading awns. Very similar E. elymoides has glumes that are entire or unevenly split into two to three parts. Determining how much the glumes are split is complicated by the presence of glumelike sterile lemmas in both E. multisetus and some E. elymoides subspecies. Elymus multisetus glumes are divided above the base. If the glumes appear to be divided to the base, the plant is more likely to be E. elymoides.

Northern temperate regions. Approximately 150 species; 12 species treated in Flora.

Some species formerly treated in Elymus have been moved to Leymus, Pascopyrum, Pseudoroegneria, and Thinopyrum. Species now treated as members of Elymus include all the species formerly treated in Sitanion and some of those from Agropyron. See discussion under Agropyron. North Asian Elymus ciliaris and E. tsukushiensis were collected in Portland 1899–1903 but have not persisted. Both have one spikelet per node, lemmas with awns curving outwards at maturity and widest leaves to 10 mm wide when flat. Reports of E. caninus from Oregon are based on misidentifications of these specimens. Elymus caninus can be distinguished from all our other Elymus species by the hairy inner surface of its glumes. When keying Elymus, measurements of spikes include the awns. Measurements of spikelets, glumes, and lemmas do not include the awns (unless specified). Rachis internodes are measured in the middle of the spike. Glume widths of lanceolate to linear glumes are measured at the widest point. Glume widths of linear to bristle-like glumes are measured about 5 mm above the base of the glumes.