Elymus lanceolatus |
Elymus texensis |
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streambank wheatgrass, streamside wild rye, thick-spike wildrye, thickspike wheatgrass |
Texan wildrye, Texas wildrye |
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Habit | Plants strongly rhizomatous, sometimes glaucous. | Plants cespitose, not rhizomatous, glaucous. | ||||||||
Culms | 22-130 cm, erect; nodes glabrous. |
70-110 cm, erect; nodes 4-6, mostly exposed, glabrous. |
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Leaves | often mostly basal, sometimes more evenly distributed; sheaths glabrous or pubescent; auricles usually present on the lower leaves, 0.5-1.5 mm; ligules 0.1-0.5 mm, erose, sometimes ciliolate; blades 1.5-6 mm wide, generally involute, abaxial surfaces usually glabrous, adaxial surfaces strigose, ribs subequal in size and spacing. |
evenly distributed; sheaths glabrous or ciliate; auricles to about 2 mm, pale to purplish brown; ligules 1-2 mm, erose; blades 2-9 mm wide, lax or somewhat involute, adaxial surfaces thinly scabrous to hirsute or densely pilose. |
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Spikes | 3.5-26 cm long, 0.5-1 cm wide, erect to slightly nodding, usually with 1 spikelet per node, sometimes with 2 at a few nodes; internodes 3.5-15 mm long, 0.1-0.8 mm wide, glabrous or hairy. |
9-20 cm long, 2-2.5 cm wide, erect to slightly nodding, with 2 spikelets per node; internodes (5)7-15(22) mm long, 0.1-0.3 mm thick at the thinnest sections, glabrous except for the ciliolate margins, with slight dorsal angles and green lateral bands along the concave sides. |
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Spikelets | 8-31 mm, 1.5-3 times longer than the internodes, appressed, with 3-11 florets; rachillas glabrous or hairy, hairs to 1 mm; disarticulation above the glumes, beneath each floret. |
13-20 mm excluding the awns, 20-40 mm including the awns, appressed, with 4-6(8) florets, lowest florets functional; disarticulation above the glumes, beneath each floret. |
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Glumes | subequal, 5-14 mm long, 1/2 - 3/4 the length of the adjacent lemmas, 0.7-1.3 mm wide, lanceolate, glabrous or hairy, smooth or scabrous, 3-5-veined, flat or weakly, often asymmetrically keeled, keels straight, margins narrow, tapering from the base or from beyond midlength, apices acute to acuminate, sometimes mucronate or shortly awned; lemmas 7-12 mm, glabrous or hairy, hairs all alike, sometimes scabrous, acute to awn-tipped, awns to 2 mm, straight; paleas about equal to the lemmas, keels straight below the apices, smooth or scabrous proximally, sometimes hairy, scabrous distally, intercostal region glabrous or with hairs, apices 0.2-0.3 mm wide; anthers (2.5)3-6 mm. |
subequal, 14-24 mm long including the undifferentiated awns, 0.1-0.3 mm wide, setaceous, entire, 0-1-veined, tapering from the base, glabrous, margins firm, awns more or less straight; lemmas 8-12 mm, smooth, glabrous, awns 8-25 mm, straight, flexuous or slightly curving; paleas 7-11 mm, obtuse or truncate; anthers 4.5-6 mm. |
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Anthesis | in May. |
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2n | = 28. |
= unknown. |
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Elymus lanceolatus |
Elymus texensis |
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Distribution |
AK; AZ; CA; CO; ID; IL; MI; MT; ND; NE; NM; NV; OR; SD; WA; WI; WY; AB; BC; MB; ON; SK; YT
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TX |
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Discussion | Elymus lanceolatus grows in sand and clay soils and dry to mesic habitats. It is found primarily in the western half of the Flora region, between the coastal mountains and 95° W longitude, with the exception of E. lanceolatus subsp. psammophilus, which extends around the Great Lakes. Three subspecies are recognized, primarily on the basis of their lemma and palea pubescence. Elymus lanceolatus is primarily outcrossing, and hybridizes with several species of Triticeae. Elymus albicans (p. 334) is thought to be derived from hybridization with the awned phase of Pseudoroegneria spicata (p. 281). Judging from specimens of controlled hybrids, hybridization with E. trachycaulus (p. 321) and unawned plants of P. spicata probably occur, but would be almost impossible to detect without careful observation in the field. Experimental hybrids are partially fertile, and capable of backcrossing to either parent (Dewey 1965, 1967, 1968, 1975, 1976). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Elymus texensis is known only from calcareous bluffs and hills in juniper woods and grassy areas on the Edwards Plateau of southwest Texas. It is known from only three collections and needs further study (Campbell 2002). It is similar to the Mexican species E. pringlei (see previous), but differs in its larger anthers, larger, less pubescent spikelets, and in its longer, glabrous rachis internodes with green lateral bands. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 24, p. 327. | FNA vol. 24, p. 312. | ||||||||
Parent taxa | Poaceae > subfam. Pooideae > tribe Triticeae > Elymus | Poaceae > subfam. Pooideae > tribe Triticeae > Elymus | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | Agropyron dasystachyum var. riparium, Agropyron dasystachyum | |||||||||
Name authority | (Scribn. & J.G. Sm.) Gould | J.J.N. Campb. | ||||||||
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