Aira praecox

L.
Common names: Spike hairgrass
Introduced
Treatment appears in FNA Volume 24. Treatment on page 616.

Plants annual; tufted. Culms 1-36 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. 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. Spikelets 2.8-3.8 mm, green and purple-tinged; rachillas prolonged beyond the base of the distal floret. 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. 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. 2n = 14.

Distribution

Md., N.J., N.C., Mass., Wash., Va., B.C., N.S., Del., Oreg., N.Y., Pa., Calif., Conn.

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.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Aira praecox"
lacerate +  and acute +
membranous +  and scarious +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
J.K. Wipff +
1 (?) +  and 3 (?) +
straight +
attached +
basal +  and terminal +
geniculate +
0.3 cm3 mm <br />0.003 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
0.25 cm2.5 mm <br />0.0025 m <br /> (5 cm50 mm <br />0.05 m <br />) +
not evident +
scabridulous +
cross +, linear +  and narrowly lanceolate +
0.3mm;2.0mm +
capillary +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
Spike hairgrass +
not branching +
1 cm10 mm <br />0.01 m <br /> (36 cm360 mm <br />0.36 m <br />) +
not woody +
Md. +, N.J. +, N.C. +, Mass. +, Wash. +, Va. +, B.C. +, N.S. +, Del. +, Oreg. +, N.Y. +, Pa. +, Calif. +  and Conn. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
compressed +
extended +
subtending +
scabridulous +
subequal +
membranous +
uncinate +
scabridulous +
lanceolate +  and ovate +
subcoriaceous +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.53 cm5.3 mm <br />0.0053 m <br />) +
membranous +
inconspicuous +
lanceolate +
0.28 cm2.8 mm <br />0.0028 m <br /> (0.36 cm3.6 mm <br />0.0036 m <br />) +
0.24 cm2.4 mm <br />0.0024 m <br /> (0.33 cm3.3 mm <br />0.0033 m <br />) +
concealed +  and prominent +
2 +  and 1 +
well-developed +
2-keeled +
0.17 cm1.7 mm <br />0.0017 m <br /> (0.21 cm2.1 mm <br />0.0021 m <br />) +
membranous +
1cm +  and 4.1cm +
spikelike +
0.3 cm3 mm <br />0.003 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
capillary +
enlarged +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.32 cm3.2 mm <br />0.0032 m <br />) +
dry +  and fleshy +
0 cm0 mm <br />0 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
scabridulous +
Introduced +
green and purple-tinged +
compressed +
0.28 cm2.8 mm <br />0.0028 m <br /> (0.38 cm3.8 mm <br />0.0038 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Aira praecox +
species +
membranous +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
0.27 cm2.7 mm <br />0.0027 m <br /> (0.38 cm3.8 mm <br />0.0038 m <br />) +
parallel +  and converging +
stoloniferous +  and rhizomatous +
aquatic +  and terrestrial +