Amelichloa brachychaeta

(Godr.) Arriaga & Barkworth
Common names: Puna needlegrass
Synonyms: Achnatherum brachychaetum
Treatment appears in FNA Volume 24. Treatment on page 182.
Please click on the illustration for a higher resolution version.
Illustrator: Cindy Roché

Copyright: Utah State University

Plants with knotty, shortly rhizomatous bases. Culms 40-90 cm tall, 1-2 (3) mm thick, erect, glabrous; nodes usually 3. Basal sheaths mostly glabrous, margins ciliate distally; collars glabrous, often with tufts of hair to 1.5 mm on the sides; ligules 0.2-0.6 mm, membranous, strigose, ciliate, cilia to 2 mm, slightly longer at the leaf margins; blades 8-35 cm long, usually convolute and 0.5-0.8 mm in diameter, 2-3 mm wide when flat, erect, abaxial surfaces smooth, adaxial surfaces usually glabrous. Panicles 10-25 cm long, 1-4 cm wide, bases sometimes included in the upper leaf-sheaths; branches ascending to spreading, longest lower branches 4-12 cm. Glumes subequal, 6-8 mm, linear-lanceolate, 1-3-veined, midveins smooth, scabridulous, or with stiff hairs, varying within a panicle, apices acuminate; florets 4-5.5 mm long, about 0.8 mm thick, fusiform; calluses 0.4-0.5 mm, blunt, strigose, hairs 0.5-0.8 mm; lemmas pubescent over and between the veins on the proximal 1/2 at least initially, hairs 0.5-0.8 mm, sometimes glabrous at maturity between the midveins and lateral-veins, distal portion glabrous, tapering to the apices, apices with 0.7-1 mm hairs around the base of the awn; awns 10-18 mm, glabrous or scabrous, usually once-geniculate; paleas 3/4 - 9/10 as long as the lemmas, pubescent over the central portion, apices involute; lodicules 3; anthers 2-2.4 (3) mm, penicillate. Caryopses 2-3 mm long, 0.9-1 mm thick, fusiform; style bases straight, centric. 2n = unknown.

Discussion

Amelichloa brachychaeta has been found at a few locations in California, where it is listed as a noxious weed. It is native to Uruguay and Argentina. It is avoided by cattle because of its sharply pointed leaves. The cleistogamous panicles, which may be at or below ground level, remain a source of seeds unless the plants are completely uprooted. Amelichloa caudata and A. clandestina (see below) are a greater problem in this regard, because they appear to produce such panicles more frequently.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Amelichloa brachychaeta"
membranous +  and scarious +
3 cm30 mm <br />0.03 m <br /> (?) +
2 +, 1 +  and 3 +
penicillate +
0.2 cm2 mm <br />0.002 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
Mirta O. Arriaga +
(Godr.) Arriaga & Barkworth +
twisted +  and not branched +
1 (?) +  and 3 (?) +
subterminal +  and eccentric +
scabrous +  and glabrous +
once-geniculate +
reduced +
1 cm10 mm <br />0.01 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
keeled +  and rounded +
rhizomatous +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
8 cm80 mm <br />0.08 m <br /> (35 cm350 mm <br />0.35 m <br />) +
not evident +
cross +, linear +  and narrowly lanceolate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
ascending;spreading +
spikelike +
well-developed +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
0 cm0 mm <br />0 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Puna needlegrass +
branching +  and not branching +
perennial +  and annual +
40 cm400 mm <br />0.4 m <br /> (90 cm900 mm <br />0.9 m <br />) +
intravaginal +  and basal +
not woody +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
0.4 cm4 mm <br />0.004 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
sometimes longer +
fusiform +
1-10-veined +
subtending +
linear-lanceolate +
subequal +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
membranous +
uncinate +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
solid +  and hollow +
basally concentrated +  and evenly distributed +
ovate +, rectangular +  and lanceolate +
membranous +  and coriaceous or indurate +
rounded +  and acute +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
membranous +
inconspicuous +
lanceolate +
fleshy +  and membranous +
scabridulous +
concealed +  and prominent +
2 +  and 1 +
well-developed +
3/4 +  and 9/10 +
reduced +
10cm +  and 25cm +
1 cm10 mm <br />0.01 m <br /> (4 cm40 mm <br />0.04 m <br />) +
dry +  and fleshy +
not prolonged +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
1 +  and 60 +
unisexual +  and bisexual +
laterally compressed +  and terete +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
plumose +
Achnatherum brachychaetum +
Amelichloa brachychaeta +
Amelichloa +
species +
membranous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
0 cm0 mm <br />0 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
inconspicuous +
aquatic +  and terrestrial +
12 +, 11 +, 10 +, 8 +  and 7 +