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side-oats grama

Chino grama

Habit Plants perennial; cespitose or not, with or without rhizomes. Plants perennial; densely cespitose, bases hard, knotty, without rhizomes or stolons.
Culms

8-80 cm, erect or decumbent, solitary or in small to large groups.

25-60 cm, numerous, somewhat woody at the base, geniculate, branching profusely from the lower nodes;

nodes usually 4-5;

lower internodes glabrous, without a conspicuous, white, chalky bloom.

Leaves

evenly distributed;

sheaths mostly glabrous, sometimes with hairs distally;

ligules 0.3-0.5 mm, membranous, ciliate;

blades 2-30 cm long (1.4)2.5-7 mm wide, at least some over 2.5 mm wide, flat or folded when dry, usually smooth abaxially and scabrous adaxially, occasionally pubescent, bases usually with papillose-based hairs on the margins.

Panicles

13-30 cm, secund, with (12)30-80 reflexed branches;

branches (5)10-30(40) mm, deciduous, with (1)2-7(15) spikelets, axes terminating 3-5 mm beyond the base of the terminal spikelets, apices entire;

disarticulation at the base of the branches.

1-3(5) cm, with 1-3(4) branches;

branches 10-35 mm, persistent, ascending to widely divergent, becoming arcuate, dark, with 24-45(64) spikelets, branches terminating in a reduced, needlelike, 2-5 mm spikelet;

disarticulation above the glumes.

Spikelets

appressed, all alike, with 1 bisexual and 1-2 sterile, rudimentary florets.

with 1 bisexual floret and 1-2 rudimentary florets.

Glumes

unequal, glabrous or scabrous;

lower glumes 2.5-6 mm, 1/2 or more as long as the upper glumes;

upper glumes 5.5-8 mm;

lowest lemmas 3-6.5 mm, glabrous or scabrous-strigose, often minutely rugose, acute or inconspicuously 3-lobed, 3-veined, veins usually extending as short mucros or awns to 6 mm;

central mucros or awns not flanked by membranous lobes;

lowest paleas acute, unawned;

anthers 1.5-3.5 mm, yellow, orange, red, or purple;

distal floret(s) 0.4-3.5 mm, sterile, variable, usually a glabrous lemma having a short membranous base, no palea, and 3 unequally-developed awns, central awns 1.5-7 mm.

acute to acuminate, glabrous or sparsely short-hairy, hairs not papillose-based;

lower glumes 2-2.5 mm;

upper glumes 2-3.5 mm;

lowest lemmas 2.5-4 mm, sparsely to densely hairy, 3-awned, awns slightly shorter than the lemma bodies, central awns flanked by 2 membranous lobes;

lowest paleas about 4.5 mm, mostly glabrous, sometimes puberulent distally, acute to acuminate, veins not excurrent, unawned;

second florets about 4.5 mm, 3-awned, awns 3-5 mm;

rachilla segments subtending second florets with densely pubescent apices;

third florets, if present, flabellate scales, 1-awned.

Caryopses

1-1.2 mm long, about 0.4 mm wide.

Ligules

0.1-0.2 mm, of hairs;

blades 2-7 cm long, 1-2 mm wide, mostly flat but the tips involute.

2n

= (20), 40, 41-103.

= 40.

Bouteloua curtipendula

Bouteloua ramosa

Distribution
from FNA
AL; AR; AZ; CA; CO; CT; DC; FL; GA; IA; ID; IL; IN; KS; KY; LA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NJ; NM; NY; OH; OK; OR; PA; SC; SD; TN; TX; UT; VA; WA; WI; WV; WY; HI; AB; BC; MB; ON; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
TX
[BONAP county map]
Discussion

Bouteloua curtipendula is a common, often dominant or co-dominant species in open grasslands and wetlands of the drier portions of the central grasslands of North America. It is highly regarded as a forage species and is also an attractive ornamental. Its range extends from the Flora region through Mexico and Central America to western South America.

As the range of chromosome numbers suggests, B. curtipendula is an apomictic species. There are three varieties. Two of the three grow in the Flora region; the third, B. curtipendula var. tenuis Gould & Kapadia, is endemic to Mexico.

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

Bouteloua ratnosa is locally common on rocky limestone slopes and flats among shrubs and Agave lecheguilla. Its range extends from the Trans Pecos region of western Texas to adjacent northern Mexico, particularly the state of Coahuila. Reeder and Reeder (1980) provide an excellent discussion of B. ramosa and B. breviseta.

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

Key
1. Plants long-rhizomatous; culms solitary or in small clumps
var. curtipendula
1. Plants not long-rhizomatous, bases sometimes knotty with short rhizomes; culms in large or small clumps
var. caespitosa
Source FNA vol. 25, p. 254. FNA vol. 25, p. 267.
Parent taxa Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Bouteloua > subg. Bouteloua Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Bouteloua > subg. Chondrosum
Sibling taxa
B. aristidoides, B. barbata, B. breviseta, B. chondrosoides, 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. kayi, B. parryi, B. radicosa, B. repens, B. rigidiseta, B. simplex, B. trifida, B. uniflora, B. warnockii
Subordinate taxa
B. curtipendula var. caespitosa, B. curtipendula var. curtipendula
Name authority (Michx.) Torr. Scribn. ex Vasey
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