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needle grama

Habit Plants annual; tufted.
Culms

4-60 cm, outer culms of a tuft decumbent, sometimes geniculate, branched at the lower nodes.

Panicles

2.5-10.5 cm, with (1)4-15 branches;

branches 5-45 mm, deciduous, densely pubescent (at least basally), with 2-10 spikelets per branch, axes extending 2-10 mm beyond the base of the terminal spikelets, apices entire;

disarticulation at the base of the branches, the break forming a sharp tip.

Spikelets

appressed.

Caryopses

2.5-3 mm.

Ligules

0.2-0.5 mm, membranous, lacerate or ciliate;

blades 2-5(9) cm long, 0.7-2 mm wide, flat or folded, adaxial surfaces sometimes with papillose-based hairs, margins usually with papillose-based hairs near the ligules.

Proximal

spikelet on each branch with 1 floret;

lower glumes 1.5-3.5 mm, glabrous, narrow to subulate;

upper glumes 5.5-6.2 mm, densely pubescent, at least on the basal 1/2;

lemmas 5.8-6 mm, acuminate, unawned;

lowest paleas almost as long as the lemmas, bifid, glabrous;

rachillas prolonged beyond the florets for about 0.5 mm.

Distal

spikelets with 1 bisexual and 1 rudimentary floret, glumes unequal, glabrous, minutely scabrous on the keels; narrowly acute or acuminate;

lower glumes 1.5-2 mm;

upper glumes 5-6 mm, glabrous or sparsely pubescent basally, often divergent;

lowest lemmas 6-8 mm, veins pubescent, lateral veins excurrent as short (to 1 mm) awns, acuminate, midvein extended into a setaceous tip or a short awn;

lowest paleas 5-7 mm, bifid, veins often excurrent as short awns;

anthers about 2.5 mm, yellow or yellow and red;

distal florets reduced to a pubescent, 3-awned, awn column, awns 2-7 mm, exserted.

2n

= 40.

Bouteloua aristidoides

Distribution
from FNA
AZ; CA; MD; NM; NV; TX; UT
[WildflowerSearch map]
[BONAP county map]
Discussion

There are two varieties, both of which grow in the Flora region.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Panicle branches with 2-5 spikelets, usually 5-16 mm to the base of the terminal spikelets, axes usually extending an additional 6-10 mm
var. aristidoides
1. Panicle branches with 6-10 spikelets, usually 15-35 mm to the base of the terminal spikelets, axes extending an additional 2-5(7) mm
var. arizonica
Source FNA vol. 25, p. 255.
Parent taxa Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Bouteloua > subg. Bouteloua
Sibling taxa
B. barbata, B. breviseta, B. chondrosoides, B. curtipendula, B. eludens, B. eriopoda, B. gracilis, B. hirsuta, B. kayi, B. parryi, B. radicosa, B. ramosa, B. repens, B. rigidiseta, B. simplex, B. trifida, B. uniflora, B. warnockii
Subordinate taxa
B. aristidoides var. aristidoides, B. aristidoides var. arizonica
Name authority (Kunth) Griseb.
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