Achnatherum nelsonii subsp. nelsonii

Common names: Nelson's needlegrass
Synonyms: Stipa columbiana var. nelsonii
Treatment appears in FNA Volume 24. Treatment on page 124.

Calluses sharp, acute to acuminate, glabrous tips 0.05-0.15 mm, dorsal boundary of the glabrous tip and the callus hairs acute; awns 19-45 mm.

Discussion

Achnatherum nelsonii subsp. nelsonii intergrades with subsp. dorei in Montana and Wyoming, and with A. occidentale subsp. pubescens in California. Its range extends from Idaho and Montana south to Nevada. It tends to grow at lower elevations than subsp. dorei.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number."prolonged" is not a number.

membranous +  and scarious +
not penicillate +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
awned +, bifid +, bilobed +  and entire +
Rounded (?) +  and Acute (?) +
0 cm0 mm <br />0 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0 cm0 mm <br />0 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Mary E. Barkworth +
(Scribn.) Barkworth +
1 (?) +  and 3 (?) +
flexuous +
subterminal +  and eccentric +
usually scabrous +  and scabridulous +
not once-geniculate +
1.9 cm19 mm <br />0.019 m <br /> (4.5 cm45 mm <br />0.045 m <br />) +
keeled +  and rounded +
glabrous or +  and sparsely densely pubescent +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
not evident +
involute +, convolute +  and flat +
1.2mm;5mm +
ascending;appressed +
spikelike +
well-developed +
acute +  and acuminate +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
pubescent +  and glabrous +
Nelson's needlegrass +
branching +  and not branching +
perennial +  and annual +
40 cm400 mm <br />0.4 m <br /> (175 cm1,750 mm <br />1.75 m <br />) +
intravaginal +  and basal +
10 cm100 mm <br />0.1 m <br /> (250 cm2,500 mm <br />2.5 m <br />) +
not woody +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
Ariz. +, Colo. +, N.Mex. +, Tex. +, Utah +, Calif. +, Oreg. +, Mont. +, Wyo. +, Wash. +, Alta. +, B.C. +, Sask. +, Yukon +, Nev. +, Idaho +  and S.Dak. +
1/5 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
sometimes longer +
fusiform +
6mm +  and 12.5mm +
subtending +
obtuse +, acute +  and acuminate +
membranous +
0.7mm +  and 1.1mm +
divergent +  and distributed +
erect +  and ascending +
uncinate +
0.5 cm5 mm <br />0.005 m <br /> (?) +
solid +  and hollow +
basally concentrated +  and evenly distributed +
0 cm0 mm <br />0 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
ovate +, rectangular +  and lanceolate +
stiffly membranous +  and coriaceous +
pubescent +  and glabrous +
membranous +
membranous +
inconspicuous +
not lobed +
concealed +  and prominent +
2 +  and 5 +
2 +  and 1 +
pubescent +  and glabrous +
well-developed +
1/3 +  and 2/3 +
not keeled +
reduced +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
9cm +  and 36cm +
0.8 cm8 mm <br />0.008 m <br /> (2 cm20 mm <br />0.02 m <br />) +
dry +  and fleshy +
not prolonged +
1 +  and 60 +
unisexual +  and bisexual +
laterally compressed +  and terete +
1 (?) +  and 3 (?) +
simple +  and compound +
Stipa columbiana var. nelsonii +
Achnatherum nelsonii subsp. nelsonii +
Achnatherum nelsonii +
subspecies +
glabrous;glabrous +
membranous +
inconspicuous +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
plant +  and cespitose +
aquatic +  and terrestrial +