Elymus macgregorii
Elymus ×pinalenoensis
early wild-rye
40-120 cm, erect or slightly decumbent;
nodes 4-8, mostly exposed, glabrous.
60-90 cm tall, about 2 mm thick.
evenly distributed;
sheaths usually glabrous, rarely villous;
auricles 2-3 mm, usually purplish black when fresh, sometimes light brown;
ligules shorter than 1 mm;
blades 7-15 mm wide, lax, dark glossy green under the glaucous bloom, adaxial surfaces usually glabrous, occasionally villous.
somewhat basally concentrated;
sheaths smooth or scabridulous;
auricles to 1.5 mm;
ligules 0.5-0.7 mm, rounded;
blades 2-2.5 mm wide, those of the basal leaves 7-15 cm long, those of the flag leaves 2-7 cm long, abaxial surfaces smooth or scabridulous, glabrous or sparsely hairy basally, veins not evident, adaxial surfaces scabrous, sometimes with scattered hairs, veins prominently and equally ribbed.
4-12 cm long, (1.7)2.2-3(4)4 cm wide, erect, exserted, with (6)9-16(20) nodes and 2 spikelets at all or most nodes, sometimes with 3 at some nodes;
internodes 4-7 mm long, about 0.3 mm thick and 2-angled at the thinnest sections, usually glabrous or scabridulous beneath the spikelets.
8-14 cm long, about 5 cm wide including the awns, about 1 cm wide excluding the awns, nodding, lower nodes with 1-2 spikelets, upper nodes with 1 spikelet;
internodes about 10 mm;
disarticulation in the rachises and beneath each floret.
10-15 mm, strongly divergent, glaucous, maturing to pale yellowish brown, with (2)3-4 florets, lowest florets functional;
disarticulation below the glumes and each floret, the lowest floret often falling with the glumes.
subequal, entire, the basal 1-3 mm terete or subterete, indurate, without evident venation, moderately bowed out, glume bodies 8-16 mm long, 1-1.8 mm wide, linear-lanceolate, widening or parallel-sided above the base, (2)4-5(8)-veined, usually glabrous, occasionally hirsute, sometimes scabrous, margins firm, awns (10)15-20(25) mm, straight except the awns of the lowest spikelets occasionally contorted;
lemmas 6-12 mm, usually glabrous, sometimes scabrous, occasionally villous, awns (15)20-30 mm, straight;
paleas 6-10 mm, apices obtuse;
anthers 2-4 mm.
22-31 mm including the awns, glume bodies 5-10 mm, midvein evident, scabrous, awns 17-26 mm, divergent, scabrous;
lemmas 11-13 mm, smooth, awns 20-40 mm, divergent, sometimes strongly divergent;
anthers about 2 mm long, 1-1.5 mm thick.
usually mid-May to mid-June.
= 28.
Elymus macgregorii
Elymus ×pinalenoensis
Elymus macgregorii grows in moist, deep, alluvial or residual, calcareous or other base-rich soils in woods and thickets, mostly east of the 100th Meridian in the contiguous United States. It used to be confused with E. glabriflorus (p. 296) or E. virginicus (p. 298), but it reaches anthesis about a month earlier than sympatric populations of these species. In most of its range, E. macgregorii has purplish black auricles; light brown auricles may be locally abundant, particularly in populations at the limits of its range.
Elymus macregorii hybridizes with several species, but especially E. virginicus and E. hystrix (p. 316) (Campbell 2000). Western plants often have smaller, more condensed spikes and distinctly villous leaves, suggesting a transition to E. virginicus var. jejunus (p. 300). Transitions to E. virginicus var. jejunus can also be recognized to the north, where the dates of anthesis are delayed, but even in Maine, E. macgregorii reaches anthesis about 10 days earlier than E. virginicus (Campbell and Haines 2002). Plants with villous lemmas grow at scattered locations; they have not been reported in distinct habitats, nor in large enough populations to warrant taxonomic recognition.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Elymus ×pinalenoensis consists of hybrids between E. elymoides subsp. brevifolius (p. 319) and E. arizonicus (p. 329) (Pyrah 1983). It has been found in the Pinaleno and Santa Catalina mountains of Graham County, Arizona, in areas disturbed by logging, road building, summer home development, and recreation.
Elymus ×pinalenoensis is an Elymus named hybrid
Elymus is notorious for its ability to hybridize. Most of its interspecific hybrids are partially fertile, permitting introgression between the parents. The descriptions provided below are restricted to the named interspecific hybrids. They should be treated with caution and some skepticism; some are based solely on the type specimen, because little other reliably identified material was available. Moreover, as the descriptions of the non-hybrid species indicate, many other interspecific hybrids exist.
The parentage of all hybrids is best determined in the field. Perennial hybrids, such as those in Elymus, can persist in an area after one or both parents have died out, but the simplest assumption is that both are present. Interspecific hybrids of Elymus that have disarticulating rachises presumably have E. elymoides or E. multisetus as one of their parents.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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