|Lisa A. Standley|
Plants perennial; usually cespitose, sometimes
shortly rhizomatous. Culms 5-130 cm, erect. Sheaths open; auricles absent; ligules membranous; blades flat
to involute, pubescent or glabrous. Inflorescences panicles,
usually dense and spikelike, sometimes lax, stiffly and narrowly pyramidal
at anthesis; main rachis and branches pubescent. Spikelets laterally
compressed, with 2-4 florets; rachillas to 1 mm, glabrous or
pubescent, usually prolonged beyond the distal florets, or bearing
a vestigial floret; disarticulation above the glumes and beneath
the florets. Glumes subequal to or slightly exceeding the lemmas,
membranous, scabrid to tomentose, keels sometimes ciliate; lower
glumes 1-veined, somewhat narrower and shorter than the upper glumes; upper
glumes obscurely 3(5)-veined; calluses with or without hairs; lemmas thin,
membranous, 5-veined, margins shining, scarious, apices acute, sometimes
mucronate or awned; paleas equaling or subequal to the lemmas,
hyaline; lodicules 2, glabrous, toothed; anthers 3; ovaries glabrous. Caryopses glabrous. x=
7. Named for Georg Ludwig Koeler (1765-1807), a botanist at Mainz.
Koeleria is a cosmopolitan genus of about 35 species that grow in dry grasslands and rocky soils; two are native to the Flora region, a third was once collected in the region but is not known to have persisted. In Europe, the genus forms a series of polyploid complexes in which cytotypes are morphologically and ecologically distinct, but species boundaries are not.
Lemmas pubescent to densely tomentose, purple; panicles 1-5 cm long; culms 5-35 cm long, finely pubescent throughout ..... 1. K. asiatica
Lemmas usually glabrous, green, sometimes purple-tinged, stramineous at maturity; panicles 4-27 cm long; culms 20-130 cm long, mostly glabrous, pubescent near the nodes and sometimes below the panicle (2)
Spikelets 2.5-6.5 mm long; old sheaths usually breaking off with age or, if disintegrating, the fibers straight or nearly straight; margins of the basal leaf blades glabrous or with hairs usually shorter than 1 mm near the base ..... 2. K. macrantha
Spikelets 6-10 mm long; old sheaths weathering to wavy, curled, or arched fibers; margins of the basal leaf blades frequently with hairs longer than 2 mm near the base ..... 3. K. pyramidata
1. Koeleria asiatica Domin
Plants cespitose, shortly rhizomatous. Culms 5-35 cm, densely and finely pubescent throughout. Basal sheaths remaining intact; ligules 0.5-2.5 mm; basal blades 2-20 cm long, 1-3 mm wide, involute, stiff, margins not ciliate, adaxial surfaces pubescent. Panicles 1-4(5) cm long, 0.7-1.5 cm wide, somewhat interrupted at the base; branches villous. Spikelets 4-6.5 mm, with 2-3 florets; rachillas pubescent. Glumes membranous, purple, scabrous, ciliate on the keels and the upper margins; lower glumes 2.5-3.5 mm long, about 0.5 mm wide, lanceolate, narrow, apices acute or awn-tipped to about 0.6 mm; upper glumes 3-4.8 mm long, 0.8-0.9 mm wide, ovate; calluses pubescent; lemmas 4-5 mm, slightly longer than the glumes, pubescent to densely tomentose, purple to almost black, apices acute or awn-tipped to about 1.4 mm; paleas equaling or slightly shorter than the lemmas; anthers 1.2-2.5 mm. 2n = 28.
Koeleria asiatica grows on gravel bars of creeks, dry tundra, and scree slopes. Its range extends from the Ural Mountains through the Kamchatka Peninsula to northern Alaska and northwestern Canada.
2. Koeleria macrantha (Ledeb.) Schult..
Junegrass, Koelerie Accrêté
Plants cespitose, sometimes loosely so. Culms 20-85(130) cm, mostly glabrous, pubescent below the panicles and near the nodes. Leaves primarily basal; sheaths pubescent or glabrous, breaking off with age or, if disintegrating into fibers, the fibers straight; ligules 0.5-2 mm; blades 2-20 cm long, 0.5-3(4.5) mm wide, flat, involute when dry, minutely scabrous, occasionally glabrous or densely pubescent, margins of the basal blades glabrous or with hairs averaging less than 1 mm near the base. Panicles 4-27 cm long, 0.5-2 cm wide, interrupted at the base, otherwise dense; branches finely pubescent to villous. Spikelets 2.5-6.5 mm, obovate to obelliptic, with 2(3) florets; rachillas pubescent. Glumes 2.5-5 mm, ovate, membranous, green, scabrous except for the ciliate keels, apices acute; calluses pubescent; lemmas 2.5-6.5 mm, membranous, shining, usually glabrous, sometimes scabrous, particularly on the keels, usually green when young, sometimes purple-tinged, stramineous at maturity, acuminate, midveins prolonged as an awn to 1 mm; paleas shorter than the lemmas; anthers 1-2.5(3) mm. 2n = 14, 28.
Koeleria macrantha is widely distributed in temperate regions of North America and Eurasia. In North America, it grows in semi-arid to mesic conditions, on dry prairies or in grassy woods, generally in sandy soil, from sea level to 3900 m. It differs from Sphenopholis intermedia, with which it is frequently confused, in its less open panicles, and in having spikelets that disarticulate above the glumes.
The species is treated here as a polymorphic, polyploid complex. North American plants have sometimes been treated as a separate species, Koeleria nitida Nutt., but no morphological characters for distinguishing them from Eurasian members of the complex are known (Greuter 1968). Some plants from Oregon and Washington have densely pubescent culms, and high-elevation populations from western North America often are densely cespitose, with very short culms and purple leaves and inflorescences, but both variants appear to intergrade with more typical plants.
3. Koeleria pyramidata (Lam.) P. Beauv.
Plants loosely cespitose, sometimes rhizomatous. Culms (30)40-90 cm, glabrous or puberulent above. Sheaths sparsely sericeous to densely pubescent, old sheaths persistent, disintegrating into wavy, curled, or arched fibers; ligules 0.5-1 mm; blades 5-24 cm long, 1-5 mm wide, flat, margins of the basal blades often ciliate below, with hairs usually more than 2 mm. Panicles 5-22 cm long, 1-3(5) cm wide; branches villous. Spikelets 6-10 mm, with 2-4(5) florets; rachillas with scattered pubescence. Glumes acute, glabrous, smooth or scabrous; lower glumes 4-5 mm, 1-veined; upper glumes 5-6 mm, 3-veined; calluses broadly rounded, pubescent; lemmas 4-6 mm, glabrous or puberulent, rarely ciliate, usually green when young, stramineous at maturity, apices acuminate to shortly aristate; anthers 2-2.5 mm. Caryopses 2.5-3.8 mm. 2n = 14.
Koeleria pyramidata, as interpreted here, is confined to Europe. Some North American records for K. pyramidata are based on robust specimens of K. macrantha; others reflect an interpretation of K. pyramidata that includes K. macrantha.