Achnatherum lobatum

(Swallen) Barkworth
Common names: Lobed needlegrass
Synonyms: Stipa lobata
Treatment appears in FNA Volume 24. Treatment on page 131.
Please click on the illustration for a higher resolution version.
Illustrator: Cindy Roché

Copyright: Utah State University

Plants cespitose, not rhizomatous. Culms 40-100 cm tall, 0.6-2.6 mm thick, glabrous or sparsely pubescent to 5 mm below the lower nodes; nodes 4. Basal sheaths becoming flat and papery in age, margins some¬times ciliate distally, cilia to 0.5 mm; collars, including the sides, glabrous or sparsely pubescent, collars of the flag leaves glabrous; basal ligules 0.2-1.3 mm, membranous, truncate, erose to ciliate, cilia about 0.05 mm; upper ligules 0.3-1 mm; blades 1-4 mm wide, abaxial surfaces smooth, adaxial surfaces scabrous. Panicles 12-28 cm long, 0.5-1.5 cm wide; branches ascending to appressed, straight, longest branches 3-6 cm. Spikelets appressed to the branches. Glumes unequal; lower glumes 9.5-12.5 mm long, 0.8-1.2 mm wide, 3 (5, 7) -veined, apices straight to somewhat recurved; upper glumes 2-3.5 mm shorter, 3-veined; florets 5.5-7.5 mm long, 0.6-1.1 mm thick, terete, widest about midlength; calluses 0.3-0.5 mm, blunt; lemmas evenly hairy, hairs at midlength 0.7-1.2 mm, fusiform, terete, apical hairs 1.3-2.2 mm, erect, usually less than 1 mm longer than those at midlength, apical lobes 0.5-1.2 mm, membranous, flexible; awns 10-22 mm, persistent, once or twice-geniculate, scabrous, terminal segments straight; paleas 3-4.3 mm, 3/5 – 3/4 as long as the lemmas, pubescent, hairs exceeding the apices, veins terminating below the apices, apices flat, rounded; anthers 3-4 mm, dehiscent, sparsely penicillate, hairs about 0.1 mm. 2n = unknown.

Discussion

Achnatherum lobatum grows on rocky, open slopes in pinyon-pine and white fir associations of southern Arizona, New Mexico, Texas, and northern Mexico, at 2100-2800 m. It flowers from mid- to late summer.

Achnatherum lobatum is similar to A. scribneri and A. perplexum. It differs from A. scribneri in its shorter apical lemma hairs and blunt calluses, and from A. perplexum in having longer lemma lobes and erect apical hairs.

Selected References

None.

Lower Taxa

None.

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

... more about "Achnatherum lobatum"
membranous +  and scarious +
penicillate +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
awned +, bifid +, bilobed +  and entire +
straight +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Mary E. Barkworth +
(Swallen) Barkworth +
1 (?) +  and 3 (?) +
flexuous +
subterminal +  and eccentric +
usually scabrous +  and scabridulous +
not once-geniculate +
1 cm10 mm <br />0.01 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
not evident +
involute +, convolute +  and flat +
1mm;4mm +
ascending;appressed +
spikelike +
well-developed +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0 cm0 mm <br />0 m <br />) +
glabrous +  and pubescent +
Lobed needlegrass +
branching +  and not branching +
perennial +  and annual +
40 cm400 mm <br />0.4 m <br /> (100 cm1,000 mm <br />1 m <br />) +
intravaginal +  and basal +
pubescent +  and glabrous +
0 cm0 mm <br />0 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
not woody +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.26 cm2.6 mm <br />0.0026 m <br />) +
Ariz. +, N.Mex. +  and Tex. +
1/5 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
0.55 cm5.5 mm <br />0.0055 m <br /> (0.75 cm7.5 mm <br />0.0075 m <br />) +
sometimes longer +
1-10-veined +
subtending +
obtuse +, acute +  and acuminate +
unequal +
membranous +
divergent +  and distributed +
terete +  and fusiform +
0.1 cm1 mm <br />0.001 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 +
3 cm30 mm <br />0.03 m <br /> (6 cm60 mm <br />0.06 m <br />) +
0.95 cm9.5 mm <br />0.0095 m <br /> (1.25 cm12.5 mm <br />0.0125 m <br />) +
7 +, 5 +  and 3 +
0.8mm +  and 1.2mm +
concealed +  and prominent +
2 +  and 1 +
pubescent +  and glabrous +
well-developed +
3/5 +  and 3/4 +
not keeled +
reduced +
0.3 cm3 mm <br />0.003 m <br /> (0.43 cm4.3 mm <br />0.0043 m <br />) +
12cm +  and 28cm +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
dry +  and fleshy +
not prolonged +
1 +  and 60 +
unisexual +  and bisexual +
laterally compressed +  and terete +
1 (?) +  and 3 (?) +
simple +  and compound +
Stipa lobata +
Achnatherum lobatum +
Achnatherum +
species +
membranous +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
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 +