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big squirreltail, big squirreltail grass

northern riverbank wildrye, Wiegand's wild-rye, élyme de Wiegand

Habit Plants cespitose, not rhizomatous. Plants cespitose, not rhizomatous, somewhat glaucous.
Culms

15-65 cm, erect to ascending, usually puberulent;

nodes 4-6, mostly concealed, glabrous.

100-180(220) cm, erect;

nodes 9-16, mostly concealed by the leaf sheaths, glabrous.

Leaves

evenly distributed;

sheaths glabrous or white-villous;

auricles usually present, 0.5-1.5 mm;

ligules to 1 mm, truncate, entire or lacerate;

blades 1.5-4(5) mm wide, often ascending and involute, adaxial surfaces scabrous, pilose, or villous.

evenly distributed;

sheaths usually glabrous, occasionally villous, often reddish brown;

auricles 1-3 mm, brown;

ligules to 1 mm;

blades (8)10-20(24) mm wide, flat, lax, dark green, adaxial surfaces usually thinly pilose, with weakly spreading hairs on the veins at least near the margins, sometimes villous or glabrous.

Spikes

5-20 cm long, 5-15 cm wide, erect, sometimes partially enclosed at the base, with 2 spikelets per node, rarely with 3-4 at some nodes;

internodes 3-5(8) mm long, 0.1-0.3 mm thick at the thinnest sections, glabrous beneath the spikelets.

10-30 cm long, 3-5 cm wide, pendent, the bases often barely exserted, with 2 spikelets per node;

internodes 5-8(12) mm long, 0.2-0.3 mm thick at the thinnest sections, usually pubescent beneath the spikelets.

Spikelets

10-15 mm, divergent, with 2-4 florets, lowest florets sterile and glumelike in 1 or both spikelets at each node;

disarticulation initially at the rachis nodes, subsequently beneath each floret.

12-20 mm, divergent, with (3)4-6(7) florets, lowest florets functional;

disarticulation above the glumes and beneath each floret.

Glumes

subequal, (10)30-100 mm including the awns, the bases indurate and glabrous, glume bodies (2)5-10 mm long, 1-2 mm wide, setaceous, 2-3-veined, margins firm, awns (8)25-90 mm, each split into 3-9 unequal divisions, scabrous, flexuous to outcurving from near the glume bases at maturity;

fertile lemmas 8-10 mm, smooth or scabrous near the apices, 2 lateral veins extending into bristles to 10 mm, awns (10)20-110 mm long, about 0.2 mm wide at the base, divergent to arcuate;

paleas 7-9 mm, veins usually extending into about 1 mm bristles, apices acute to truncate;

anthers 1-2 mm.

equal or subequal, 12-30 mm including the often undifferentiated awns, the basal 0.5-1 mm subterete and slightly indurate, glume bodies 7-12 mm long, (0.2)0.4-0.9(1.1) mm wide, linear-setiform, entire, widening or parallel-sided above the base, 1-3(5)-veined, glabrous, hispidulous or villous, especially near the margins, margins firm, awns (5)8-15(18) mm, straight or flexuous;

lemmas 10-15 mm, usually uniformly appressed-villous, rarely scabrous-hirtellous or glabrous, awns 15-25(30) mm, moderately to strongly outcurving;

paleas 9-14 mm, narrowly truncate, minutely bidentate;

anthers 2-3.5 mm.

Anthesis

from late May to June.

from mid-July to early August.

2n

= 28.

= 28.

Elymus multisetus

Elymus wiegandii

Distribution
from FNA
AZ; CA; CO; ID; NV; OR; UT; WA; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
CT; IA; KY; MA; ME; MI; MN; ND; NH; NJ; NY; PA; SD; VT; WI; WY; NB; ON; QC; SK
[WildflowerSearch map]
[BONAP county map]
Discussion

Elymus multisetus grows in dry, often rocky, open woods and thickets on slopes and plains, from central Washington and Idaho to southern California, Colorado, and northwestern Arizona, and from sea level to 2000 m. It has also been reported from Baja California, Mexico. It usually grows in less arid habitats than E. elymoides subsp. elymoides (p. 319), but the two taxa are sometimes sympatric.

Wilson (1963) reported a wide belt of introgression between Elymus multisetus and E. elymoides subsp. elymoides from southeastern California to southern Nevada, but not in other areas where they are sympatric. There are also probable hybrids with E. glaucus (p. 306) and Pseudoroegneria spicata (p. 281).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Elymus wiegandii grows in moist or damp, rich, alluvial soil, especially on sandy river terraces and in woods and thickets, primarily from Saskatchewan through much of the Great Lakes region to Nova Scotia and Connecticut. It has abnormal neocentric chromosomes with meiotic irregularities that appear to limit the fertility of its hybrids, and even some crosses within the species (Vilkomerson 1950). It may be derived from hybrids between E. canadensis (p. 303) and perhaps E. riparius (p. 302). The latter species is similar to E. wiegandii and overlaps with it in range and habitat within the Great Lakes region, where there are a few plants that appear to be hybrids between the two. Plants with scabrous-hirtellous or glabrous lemmas (E. wiegandii f. calvescens Fernald) are known from Maine and New Hampshire.

Elymus wiegandii is often confused with sympatric E. canadensis and E. diversiglumis (p. 316), but it has a distinctive robust, broad-leaved habit. It is intermediate between the two in spike density and glume development. Occasional plants with glabrous leaves and less pendent spikes suggest introgression from E. canadensis, but artificial crosses produced no fertile Fj plants (Church 1958).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 24, p. 318. FNA vol. 24, p. 305.
Parent taxa Poaceae > subfam. Pooideae > tribe Triticeae > Elymus Poaceae > subfam. Pooideae > tribe Triticeae > Elymus
Sibling taxa
E. alaskanus, E. albicans, E. arizonicus, E. bakeri, E. canadensis, E. caninus, E. churchii, E. ciliaris, E. curvatus, E. dahuricus, E. diversiglumis, E. elymoides, E. glabriflorus, E. glaucus, E. hirsutus, E. hoffmannii, E. hystrix, E. interruptus, E. lanceolatus, E. macgregorii, E. macrourus, E. pringlei, E. repens, E. riparius, E. scribneri, E. semicostatus, E. sibiricus, E. sierrae, E. stebbinsii, E. svensonii, E. texensis, E. trachycaulus, E. tsukushiensis, E. villosus, E. violaceus, E. virginicus, E. wawawaiensis, E. wiegandii, E. ×cayouetteorum, E. ×ebingeri, E. ×hansenii, E. ×palmerensis, E. ×pinalenoensis, E. ×pseudorepens, E. ×saundersii, E. ×yukonensis
E. alaskanus, E. albicans, E. arizonicus, E. bakeri, E. canadensis, E. caninus, E. churchii, E. ciliaris, E. curvatus, E. dahuricus, E. diversiglumis, E. elymoides, E. glabriflorus, E. glaucus, E. hirsutus, E. hoffmannii, E. hystrix, E. interruptus, E. lanceolatus, E. macgregorii, E. macrourus, E. multisetus, E. pringlei, E. repens, E. riparius, E. scribneri, E. semicostatus, E. sibiricus, E. sierrae, E. stebbinsii, E. svensonii, E. texensis, E. trachycaulus, E. tsukushiensis, E. villosus, E. violaceus, E. virginicus, E. wawawaiensis, E. ×cayouetteorum, E. ×ebingeri, E. ×hansenii, E. ×palmerensis, E. ×pinalenoensis, E. ×pseudorepens, E. ×saundersii, E. ×yukonensis
Synonyms E. canadensis var. wiegandii
Name authority (J.G. Sm.) Burtt Davy Fernald
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