Bouteloua

Lag.
Treatment appears in FNA Volume 25. Treatment on page 250.
 TaxonIllustrator 
FNA25 P100 Bouteloua pg 263.jpegBouteloua gracilis
Bouteloua hirsuta subsp. hirsuta
Bouteloua hirsuta subsp. pectinata
Bouteloua eriopoda
Cindy Roché
Linda A. Vorobik
Cindy Roché
Linda A. Vorobik
Cindy Roché
Linda A. Vorobik
Cindy Roché
Linda A. Vorobik
FNA25 P101 Bouteloua pg 266.jpegBouteloua trifida
Bouteloua trifida var. burkii
Bouteloua trifida var. trifida
Bouteloua kayi
Bouteloua barbata
Bouteloua barbata var. barbata
Bouteloua barbata var. rothrockii
Cindy Roché
Linda A. Vorobik
Cindy Roché
Linda A. Vorobik
Cindy Roché
Linda A. Vorobik
Cindy Roché
Linda A. Vorobik
Cindy Roché
Linda A. Vorobik
Cindy Roché
Linda A. Vorobik
Cindy Roché
Linda A. Vorobik
FNA25 P102 Bouteloua pg 268.jpegBouteloua simplex
Bouteloua parryi
Bouteloua breviseta
Bouteloua ramosa
Cindy Roché
Linda A. Vorobik
Cindy Roché
Linda A. Vorobik
Cindy Roché
Linda A. Vorobik
Cindy Roché
Linda A. Vorobik
... further results

Plants annual or perennial; synoecious; habit various, cespitose, stoloniferous, or rhizomatous. Culms 1-80 cm. Leaves usually mostly basal; sheaths open; ligules of hairs, membranous, or membranous and ciliate. Inflorescences terminal, panicles of 1-80 solitary, spikelike branches, exceeding the upper leaves; branches 4-50 (75) mm, not woody, 1-sided, usually racemose on elongate rachises, sometimes digitate or subdigitate, with 1-130+ sessile to subsessile spikelets in 2 rows, axes terminating in a spikelet or extending beyond the base of the distal spikelet. Spikelets closely imbricate, appressed to pectinate, laterally compressed or terete, with 1-2 (3) florets, lowest floret in each spikelet bisexual, distal florets staminate or sterile; disarticulation at the base of the branches or above the glumes. Glumes unequal or subequal, 1 or both glumes equaled or exceeded by the distal floret, 1-veined, acute or acuminate, sometimes shortly awned; lower glumes usually shorter than the lowest floret; lemmas of lowest florets entire, bilobed, trilobed, or 4-lobed, 3-veined, veins usually extended into 3 short awns; paleas of lowest florets 2-veined, veins sometimes excurrent; distal floret (s) staminate or sterile, varying from similar to the lowest floret in shape, size, and venation to sterile and reduced to an awn column with well-developed awns or to a flabellate scale, x = 10.

Distribution

Conn., N.J., N.Y., W.Va., Mich., Alta., B.C., Man., Ont., Sask., D.C, Wis., Ariz., N.Mex., Pacific Islands (Hawaii), Idaho, Oreg., Fla., Wyo., Tex., La., Md., Maine, Miss., S.C., N.C., Nebr., Tenn., Pa., Mass., Ala., Ga., Ill., Ind., Ky., Minn., N.Dak., Ohio, S.Dak., Utah, Mont., Va., Colo., Calif., Puerto Rico, Virgin Islands, Kans., Okla., Ark., Iowa, Nev., Wash., Mo.

Discussion

Bouteloua, a genus of the Western Hemisphere with its center of diversity in Mexico, has about 40 species; all 19 species treated here are native to the Flora region. Several of its taxa are important forage grasses, and some are important constituents of the native North American grasslands. Two that are particularly important in North America are Bouteloua curtipendula and B. gracilis. These were major constituents of the shortgrass prairie that once covered the drier portions of the Great Plains. Both are excellent forage species. Irrigation has converted much of the area they once occupided to agricultural use, but large areas of Bouteloua grasslands remain.

Based on molecular data and morphological similarities in the non-pistillate characters, Columbus (1999) recommended expanding Bouteloua to include Buchloë, Opizia, and Cathestecum, plus some other small genera not known from the Flora region. The traditional treatment is adopted here, pending corroboration from a wider range of data, both molecular and morphological.

Key

1 Panicle branches deciduous, disarticulation occurring at their bases; spikelets usually 1-15 per branch, usually appressed rather than pectinate (subg. Bouteloua). > 2
2 All or most panicle branches with 1 spikelet Bouteloua uniflora
2 All or most panicle branches with 2-15 spikelets. > 3
3 First (proximal) spikelet on each branch with 1 floret, the remaining spikelets with 2 florets; plants annual; panicles with 1-15 branches Bouteloua aristidoides
3 Spikelets all alike or with 2 or more florets; plants annual or perennial; panicles with 1-80 branches. > 4
4 Central awns of lemmas flanked by 2 membranous lobes at maturity, the lobes 0.5-1.5 mm. > 5
5 Upper glumes bilobed, awned, the awns arising from between the teeth; inflorescence branch axes with deeply bi- or trifurcate apices; second florets sterile, rudimentary Bouteloua rigidiseta
5 Upper glumes acute, unawned or awn-tipped; inflorescence branch axes with apices entire; second florets usually staminate. > 6
6 Base of plants dense, hard and knotty; culms straight, unbranched; panicle branches (15)20-30 mm long; plants rhizomatous Bouteloua radicosa
6 Base of plants usually not dense, hard, or knotty; culms straight or geniculate, branching; panicle branches 10-20 mm long; plants not rhizomatous Bouteloua repens
4 Central awns of lemmas, if present, not flanked by membranous lobes or the lobes less than 0.3 mm long. > 5
7 Upper glumes with hairs, at least over the midveins. > 8
8 Upper glumes with hairs only over the veins Bouteloua repens
8 Upper glumes with hairs over the veins and elsewhere. > 9
9 Panicles 6-10 cm long; branches with 2-6 spikelets Bouteloua eludens
9 Panicles 2.5-6 cm long; branches with 8-12 spikelets Bouteloua chondrosoides
7 Upper glumes glabrous, sometimes scabrous. > 8
10 Second florets sterile, usually rudimentary, usually without paleas; central awns rarely to 7 mm long; panicles with 9-80 branches. > 11
11 At least some leaf blades more than 2.5 mm wide, flat or folded when dry; ligules 0.3-0.5 mm long; anthers yellow, orange, red, or purple Bouteloua curtipendula
11 Leaf blades 1-1.5(2.5) mm wide, involute when dry; ligules 1-1.5 mm long; anthers dark purple Bouteloua warnockii
10 Second florets bisexual, pistillate or staminate, with well-developed paleas; central awns 4-10 mm long; panicles with 2-17 branches. > 11
12 Base of plants dense, hard and knotty; culms straight, unbranched; panicle branches (15)20-30 mm long; plants rhizomatous Bouteloua radicosa
12 Base of plants usually not dense, hard, or knotty; culms straight or geniculate, branching; panicle branches 10-20 mm long; plants not rhizomatous Bouteloua repens
1 Panicle branches persistent; disarticulation above the glumes; spikelets 6-130 or more per branch, pectinate (subg. Chondrosum). > 2
13 Upper glumes of at least some spikelets with papillose-based hairs. > 14
14 Panicle branches extending beyond the base of the terminal spikelets Bouteloua hirsuta
14 Panicle branches terminating in a spikelet. > 15
15 Plants tufted annuals or short-lived stoloniferous perennials; panicle branches 4-8, the axes with papillose-based hairs; lowest lemmas 3-4 mm long Bouteloua parryi
15 Plants perennial, often shortly rhizomatous; panicle branches 1-3(6), the axes scabrous, never with papillose-based hairs; lowest lemmas 3.5-6 mm long Bouteloua gracilis
13 Upper glumes glabrous, scabrous, or hairy, but the hairs not papillose-based. > 14
16 Lower cauline internodes woolly-pubescent Bouteloua eriopoda
16 Lower cauline internodes glabrous or mostly so, sometimes pubescent immediately below the nodes. > 17
17 Central awns of lemmas not flanked by membranous lobes Bouteloua trifida
17 Central awns of lemmas flanked by 2 membranous lobes. > 18
18 Lowest paleas in the spikelets awned, awns 1-2 mm long; panicles with 2-20 branches. > 19
19 Lowest lemmas glabrous, with awns 3-4 mm long; panicle branches with 6-20 spikelets; plants perennial Bouteloua kayi
19 Lowest lemmas densely pilose, with awns 0.5-3 mm long; panicle branches with 20-50 spikelets; plants annual or short-lived perennials Bouteloua barbata
18 Lowest paleas in the spikelets unawned, but the veins sometimes excurrent for less than 1 mm; panicles with 1-6 branches. > 19
20 Plants annual Bouteloua simplex
20 Plants perennial. > 21
21 Culms usually with 2-3 nodes, not woody at the base; caryopses 2.5-3 mm long; lower paleas shallowly bilobed, the veins sometimes excurrent Bouteloua gracilis
21 Culms usually with 4-5 nodes, somewhat woody at the base; caryopses 1-1.2 mm long; lower paleas acute to acuminate, the veins not excurrent. > 22
22 Lower culm internodes with a thick, white, chalky bloom distally; panicle branches stramineous, mostly appressed, usually straight to slightly arcuate; plants rhizomatous, growing on gypsum soils Bouteloua breviseta
22 Lower culm internodes without a conspicuous bloom; panicle branches dark, mostly ascending to widely divergent, usually becoming arcuate; plants not rhizomatous, growing on limestone soils Bouteloua ramosa

"decumbent" is not a number.

... more about "Bouteloua"
1 +  and 3 +
J.K. Wipff +
1 (?) +  and 3 (?) +
well-developed +
keeled +  and rounded +
pseudopetiolate +  and branching +
not fused +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
not pseudopetiolate +
pubescent +  and glabrous +
usually linear +  and lanceolate occasionally ovate +
subdigitate +  and digitate +
75 cm750 mm <br />0.75 m <br /> (?) +
spikelike +
0.4 cm4 mm <br />0.004 m <br /> (5 cm50 mm <br />0.05 m <br />) +
not woody +
triangular +  and dome--shaped +
sometimes longer +
membranous +
ascending +  and erect +
1 cm10 mm <br />0.01 m <br /> (80 cm800 mm <br />0.8 m <br />) +
not woody +
Conn. +, N.J. +, N.Y. +, W.Va. +, Mich. +, Alta. +, B.C. +, Man. +, Ont. +, Sask. +, D.C +, Wis. +, Ariz. +, N.Mex. +, Pacific Islands (Hawaii) +, Idaho +, Oreg. +, Fla. +, Wyo. +, Tex. +, La. +, Md. +, Maine +, Miss. +, S.C. +, N.C. +, Nebr. +, Tenn. +, Pa. +, Mass. +, Ala. +, Ga. +, Ill. +, Ind. +, Ky. +, Minn. +, N.Dak. +, Ohio +, S.Dak. +, Utah +, Mont. +, Va. +, Colo. +, Calif. +, Puerto Rico +, Virgin Islands +, Kans. +, Okla. +, Ark. +, Iowa +, Nev. +, Wash. +  and Mo. +
not waisted +
capillary +
pistillate +  and staminate +
4-lobed +  and trilobed +
sometimes longer +
1 +  and 2 +
bisexual +  and fertile +
round +  and compressed +
reduced +
shorter or longer +
subtending +
both +  and 1 +
acuminate +  and acute +
subequal +  and unequal +
uncinate +
paniculate +  and racemose +
hollow +  and solid +
not absent +
5-veined +, 7-13-veined +  and 1-3-veined +
sometimes longer +
membranous +
inconspicuous +
concealed +  and prominent +
2 +  and 1 +
dry +  and fleshy +
spikelike +
elongate +
columbus1999a +, esparza1996a +, gould1979a +, griffiths1912a +, reeder1980a +, reeder1990a +  and wipff1996b +
flabellate +
sessile +  and subsessile +
1 +  and 130 +
terete +, compressed +  and pectinate +
1 +  and 3 +
compound +  and simple +
2 (?) +  and 3 (?) +
Gramineae +
Bouteloua +
Poaceae tribe Cynodonteae +
membranous +
7 (?) +  and 13 (?) +
extended +
rhizomatous +  and stoloniferous +
perennial +  and annual +
plant +  and cespitose +
aquatic +  and terrestrial +