Aira praecox |
Aira caryophyllea |
|||||||||
---|---|---|---|---|---|---|---|---|---|---|
early airgrass, early hair-grass, early silver-hair grass, spike hairgrass, yellow hairgrass |
common silver-hairgrass, silver hair grass, silvery hairgrass |
|||||||||
Habit | Plants annual; tufted. | Plants annual; tufted. | ||||||||
Culms | 1-36 cm, erect. |
4.5-55 cm, erect. |
||||||||
Sheaths | 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. |
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. |
||||||||
Panicles | (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. |
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. |
||||||||
Spikelets | 2.8-3.8 mm, green and purple-tinged; rachillas prolonged beyond the base of the distal floret. |
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. |
||||||||
Glumes | 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. |
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. |
||||||||
Caryopses | 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. |
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. |
||||||||
2n | = 14. |
= 14. |
||||||||
Aira praecox |
Aira caryophyllea |
|||||||||
Distribution |
CA; CT; DE; MA; MD; NC; NJ; NY; OR; PA; VA; WA; BC; NS
|
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
|
||||||||
Discussion | 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.) |
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.) |
||||||||
Key |
|
|||||||||
Source | FNA vol. 24, p. 616. | FNA vol. 24, p. 615. | ||||||||
Parent taxa | Poaceae > subfam. Pooideae > tribe Poeae > Aira | Poaceae > subfam. Pooideae > tribe Poeae > Aira | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Name authority | L. | L. | ||||||||
Web links |
|
|