Elymus semicostatus

(Nees ex Steud.) Melderis
Synonyms: Agropyron semicostatutn
Treatment appears in FNA Volume 24. Treatment on page 338.

Plants cespitose, not rhizomatous. Culms 45-135 cm, erect or geniculately ascending, glabrous. Sheaths glabrous or villous; auricles to 1.5 mm; ligules 0.5-1.5 mm, truncate; blades 15-30 cm long, 4-12 mm wide, sometimes villous, adaxial surfaces smooth or scabrous, primary and secondary-veins alternating. Spikes 8-30 cm long, 1-2 cm wide including the awns, 0.5-1 cm wide excluding the awns, erect or nodding, usually with 1 spikelet per node, sometimes with 2 spikelets at the lower nodes; internodes 10-20 mm long, about 0.8 mm wide, scabrous on the margins and on the surfaces, marginal prickles larger than those on the surfaces, hirtellous just below the spikelets. Spikelets 16-30 mm, loosely appressed, with 6-8 florets; rachilla internodes about 0.8 mm, strigose, hairs to about 0.3 mm; disarticulation above the glumes, beneath each floret. Glumes subequal, 10-18 mm long, 1.1-2 mm wide, elliptic-lanceolate, green, not keeled, 5-7-veined, veins more or less equally prominent, scabrous, apices acute to acuminate; lemmas 10-14 mm, scabrous or puberulent dorsally, awned, awns (4) 12-18 mm, straight; paleas 3/4 as long as to slightly shorter than the lemmas, keels outwardly curved below the apices, apices 0.3-0.7 mm wide, truncate; anthers 3-6 mm. 2n = 28.

Discussion

Elymus semicostatus is native to central Asia, from Afghanistan through Pakistan to northeastern India (Sikkim). Reports of its presence in the Flora region appear to be based on misidentifications.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Elymus semicostatus"
membranous +  and scarious +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
acute +  and acuminate +
0.3mm;0.7mm +
0 cm0 mm <br />0 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
Mary E. Barkworth +, Julian J.N. Campbell +  and Bjorn Salomon +
(Nees ex Steud.) Melderis +
1 (?) +  and 3 (?) +
4 cm40 mm <br />0.04 m <br /> (?) +
straight +
basal +  and apical +
from the sinus +  and terminal +
not geniculate +
1.2 cm12 mm <br />0.012 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
15 cm150 mm <br />0.15 m <br /> (30 cm300 mm <br />0.3 m <br />) +
not evident +
cross +, linear +  and narrowly lanceolate +
0.4 cm4 mm <br />0.004 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
spikelike +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
hairy +  and glabrous +
not branching +
sometimes strongly decumbent +  and prostrate +
ascending +  and erect +
45 cm450 mm <br />0.45 m <br /> (135 cm1,350 mm <br />1.35 m <br />) +
not woody +
Oreg. +  and Ga. +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
6 +  and 8 +
laterally compressed +  and terete +
shorter than to longer than the adjacent florets +
10mm +  and 18mm +
subtending +
not keeled +  and elliptic-lanceolate +
subequal +
1.1mm +  and 2mm +
uncinate +
solid +  and hollow +
1.5 cm15 mm <br />0.015 m <br /> (?) +
10mm +  and 20mm +
0.2 cm2 mm <br />0.002 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (?) +
ciliate +  and scabrous +
distributed +
puberulent +  and scabrous +
linear-lanceolate +
1 cm10 mm <br />0.01 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
stiffly membranous +  and coriaceous +
erose +  and entire +
acute +, rounded +  and truncate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
membranous +
inconspicuous +
lanceolate +
fleshy +  and membranous +
concealed +  and prominent +
2 +  and 1 +
hairy +  and glabrous +
well-developed +
slightly longer +
subequal +
dry +  and fleshy +
spikelike +
villous +  and glabrous +
8 cm80 mm <br />0.08 m <br /> (?) +  and 30 cm300 mm <br />0.3 m <br /> (?) +
subsessile +  and sessile +
bisexual +  and sterile +
terete +  and compressed +
1.6 cm16 mm <br />0.016 m <br /> (3 cm30 mm <br />0.03 m <br />) +
1 +  and 3 +
simple +  and compound +
2 (?) +  and 3 (?) +
not papillate +
Agropyron semicostatutn +
Elymus semicostatus +
species +
membranous +
0 cm0 mm <br />0 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
unequal +
plant +  and cespitose +
aquatic +  and terrestrial +