Achnatherum nelsonii subsp. dorei

(Barkworth & J.R. Maze) Barkworth
Common names: Dore's needlegrass
Endemic
Synonyms: Stipa nelsonii var. dorei Stipa nelsonii subsp. dorei
Treatment appears in FNA Volume 24. Treatment on page 124.

Calluses blunt, glabrous tips 0.02-0.06 mm, dorsal boundary of the glabrous tip and the callus hairs almost straight to rounded; awns 19-31 mm.

Discussion

Achnatherum nelsonii subsp. dorei grows from the southern Yukon Territory to California and Wyoming. In regions where both subspecies grow, subsp. dorei is at higher elevations than subsp. nelsonii. It differs from A. rohustum in the sparsely hairy collars of its flag leaves.

Reports of Achnatherum nelsonii subsp. dorei (identified as Stipa columbiana Macoun by many authors) from New Mexico and Arizona are probably based on A. perplexum, which differs in having sparse, narrow inflorescences and slightly recurved glumes. The two also differ in flowering time, A. nelsonii subsp. dorei flowering in late spring to early summer and A. perplexum in the fall. Achnatherum nelsonii subsp. nelsonii is present in New Mexico. Scagel and Maze (1984) concluded that putative hybrids between A. nelsonii subsp. dorei and A. richardsonii were merely large plants of A. nelsonii subsp. dorei that varied in the direction of A. richardsonii.

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 +
(Barkworth & J.R. Maze) Barkworth +
1 (?) +  and 3 (?) +
flexuous +
subterminal +  and eccentric +
usually scabrous +  and scabridulous +
not once-geniculate +
1.9 cm19 mm <br />0.019 m <br /> (3.1 cm31 mm <br />0.031 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 +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
pubescent +  and glabrous +
Dore'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 nelsonii var. dorei +  and Stipa nelsonii subsp. dorei +
Achnatherum nelsonii subsp. dorei +
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 +