Aira caryophyllea |
Aira praecox |
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common silver-hairgrass, silver hair grass, silvery hairgrass |
early airgrass, early hair-grass, early silver-hair grass, spike hairgrass, yellow hairgrass |
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Habit | Plants annual; tufted. | Plants annual; tufted. | ||||||||
Culms | 4.5-55 cm, erect. |
1-36 cm, erect. |
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Sheaths | scabridulous, occasionally smooth; ligules 1.2-8 mm, abaxial surfaces scabridulous, acute to subobtuse, becoming lacerate; blades 0.3-13.5 cm long, 0.3-2.5 mm wide, antrorsely scabridulous, glabrous, apices prow-tipped. |
usually scabridulous, occasionally smooth; ligules 1.4-5.3 mm, abaxial surfaces scabridulous, acute, becoming lacerate; blades (0.1) 0.25-5 cm long, 0.3-2.0 mm wide, antrorsely scabridulous, glabrous, prow-tipped. |
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Panicles | 1.2-13.5 cm long, 1.5-10 cm wide, open; primary branches to 7.3 cm, ascending to divergent, antrorsely scabridulous, occasionally smooth; pedicels 0.9-11.3 mm, apices enlarged. |
(0.5)1-4.1 cm long, 0.3-0.7 cm wide, sometimes reduced to a single spikelet in depauperate specimens; primary branches to 1.5 cm, appressed to the rachises, antrorsely scabridulous; pedicels 0.7-3.2 mm, enlarged at the apices. |
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Spikelets | 1.7-3.3(3.5) mm, silvery-green to stramineous or purplish; rachillas usually not prolonged beyond the base of the distal floret, sometimes prolonged, vestigial. |
2.8-3.8 mm, green and purple-tinged; rachillas prolonged beyond the base of the distal floret. |
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Glumes | subequal to equal, 1.3-3.3(3.5) mm, scabridulous on the upper 1/2; callus hairs 0.2-0.4 mm; lemmas 1.3-2.6 mm, apices bifid, sometimes only the upper lemma awned, awns 2.1-3.9 mm, straight or geniculate; paleas 0.9-1.7 mm; anthers 0.2-0.5 mm. |
subequal, antrorsely scabridulous, especially on the midveins; lower glumes 2.8-3.6 mm, 1-3-veined; upper glumes 2.7-3.8 mm, 3-veined; callus hairs 0.3-0.5 mm; lower lemmas 2.4-3.3 mm, apices bifid, teeth 0.3-0.5 mm, awned, awns 3-4.5 mm; paleas 1.7-2.1 mm; upper lemmas similar; anthers 0.2-0.4 mm, yellow. |
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Caryopses | 0.9-1.5 mm long, 0.3-0.5 mm wide, abaxial surfaces grooved in the distal 1/2, adaxial surfaces grooved the entire length. |
1.3-1.7 mm long, 0.4-0.5 mm wide, glabrous, abaxial surfaces grooved 0.8-1 mm distally, adaxial surfaces grooved the entire length. |
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2n | = 14. |
= 14. |
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Aira caryophyllea |
Aira praecox |
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Distribution |
AK; AL; AR; CA; CT; DC; DE; FL; GA; ID; IL; IN; LA; MA; MD; MO; MS; NC; NH; NJ; NY; OH; OK; OR; PA; SC; TN; TX; VA; VT; WA; WY; HI; BC; NS; YT
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CA; CT; DE; MA; MD; NC; NJ; NY; OR; PA; VA; WA; BC; NS
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Discussion | Aira caryophyllea is native to Eurasia and Africa; it has become established in the Flora region, primarily on the Pacific, Gulf, and Atlantic coasts, and through much of the southeastern United States. It is usually found in disturbed areas, in vernally moist to dry, sandy to rocky, open sites, from sea level to subalpine elevations. It sometimes invades lawns or rock gardens. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Aira praecox is native to Europe. In the Flora region, it grows mainly along or near the Pacific and Atlantic coasts, in dry to vernally moist sand dunes or in sandy to rocky soils, on rock faces and ledges, and in disturbed areas such as the edges of roads, railways, and airports. It is usually found in lowland areas, though it occasionally grows at montane to subalpine elevations. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 24, p. 615. | FNA vol. 24, p. 616. | ||||||||
Parent taxa | ||||||||||
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Name authority | L. | L. | ||||||||
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