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needle grama

Kay's grama

Habit Plants annual; tufted. Plants perennial; cespitose, without rhizomes or stolons.
Culms

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

10-50 cm, erect;

nodes glabrous;

internodes glabrous, scabridulous between the veins.

Leaves

mostly basal;

sheaths scabridulous or glabrous, sparsely pubescent basally;

ligules 0.3-0.5 mm, membranous, ciliate;

blades to 20 cm long, 0.5-1.5 mm wide, involute, scabridulous adaxially.

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.

8-11 cm, with 7-20 branches;

branches 15-30 mm, persistent, with (6)14-20 pedicellate spikelets, axes terminating in a spikelet;

pedicels 0.6-0.8 mm;

disarticulation above the glumes.

Spikelets

appressed.

6-8 mm, pectinate, with 1 bisexual and 1 rudimentary floret.

Glumes

subequal, 2.5-4 mm, glabrous, acute or bidentate, midvein sometimes excurrent as a mucro or short awn;

lowest lemmas 5-7 mm, glabrous, 3-awned, awns 3-4 mm, central awns flanked by 2 membranous, acuminate, 0.4—0.6 mm lobes;

lowest paleas sometimes reduced to 2 awns, awns 1-2 mm, anthers 1.2-1.3 mm, yellow;

second florets glabrous, reduced to 1-3 awns, awns 3-4 mm.

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.

= unknown.

Bouteloua aristidoides

Bouteloua kayi

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

Bouteloua kayi is only known from the mountainous limestone terrain along the Rio Grande River in south-western Brewster County, Texas, at 2200-2500 m. Superficially, it resembles B. trifida.

(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. FNA vol. 25, p. 264.
Parent taxa Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Bouteloua > subg. Bouteloua Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Bouteloua > subg. Chondrosum
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
B. aristidoides, B. barbata, B. breviseta, B. chondrosoides, B. curtipendula, B. eludens, B. eriopoda, B. gracilis, B. hirsuta, 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. Warnock
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