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broom bluestem, little bluestem

crimson bluestem

Habit Plants cespitose or rhizomatous, green to purplish, sometimes glaucous. Plants cespitose.
Culms

7-210 cm tall, usually 1-3 mm thick, not rooting or branching at the lower nodes.

40-120 cm, erect, not rooting or branching at the lower nodes, glabrous.

Sheaths

rounded or keeled, glabrous or pubescent, sometimes glaucous;

ligules 0.5-2 mm, collars neither elongate nor narrowed;

blades 7-105 cm long, 1.5-9 mm wide, without a longitudinal stripe of white, spongy tissue.

glabrous, rounded;

ligules 0.7-2 mm;

blades 7-20 cm long, 1-6 mm wide, usually with long, papillose-based hairs basally, glabrous elsewhere, sometimes scabrous, without a longitudinal stripe of white, spongy tissue.

Peduncles

0.8-10 cm;

rames 2.5-8 cm, partially to completely exserted, usually somewhat open;

internodes 3-7 mm, usually arcuate at maturity, ciliate on at least the distal 1/2 (sometimes throughout), hairs 1.5-6 mm.

4-6 cm;

rames 4-15 cm, not open, usually almost fully exserted at maturity;

internodes 4-6 mm, straight, from mostly glabrous with a tuft of hairs at the base to densely hirsute all over.

Pedicels

3-7.5 mm long, 0.1-0.2 mm wide at the base, flaring above midlength to 0.3-0.5 mm, straight or curving outwards.

3-6 mm long, 0.3-0.5 mm wide at the base, gradually widening to about 0.6-0.8 mm at the top, straight.

Sessile

spikelets 3-11 mm;

calluses 0.5-1(2) mm, hairs 0.3-4 mm;

lower glumes glabrous;

upper lemmas membranous throughout, cleft to 1/2 their length;

awns 2.5-17 mm.

spikelets 5-9 mm;

calluses 0.5-1 mm, hairs to 2 mm;

lower glumes glabrous or densely pubescent;

upper lemmas cleft for (2/3)3/4-7/8 of their length;

awns 15-25 mm.

Pedicellate

spikelets 0.7-10 mm, sometimes shorter than the sessile spikelets, sterile or staminate, unawned or awned, awns to 4 mm, when sterile, the lemma usually absent.

spikelets 3-5 mm, usually evidently shorter than the sessile spikelets, sterile or staminate, awned, awns 0.3-6 mm.

2n

= 40.

Schizachyrium scoparium

Schizachyrium sanguineum

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

Schizachyrium scoparium is a widespread grassland species extending from Canada to Mexico. It is one of the principal grasses in the tallgrass prairies that used to dominate the central plains of North America. It exhibits considerable variation, much of it clinal. The following varieties are recognized because they are morphologically, ecologically, and geographically distinctive.

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

Schizachyrium sanguineum extends from the southern United States to Chile, Paraguay, and Uruguay.

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

Key
1. Plants not cespitose, strongly rhizomatous; pedicellate spikelets sterile
var. stoloniferum
1. Plants usually cespitose, not or shortly rhizomatous; pedicellate spikelets staminate or sterile.
→ 2
2. Pedicellate spikelets of the proximal spikelet units on each rame staminate, 5-10 mm long, with a lemma, pedicellate spikelets of the distal units usually smaller (1-4 mm) and sterile; sheaths and blades densely tomentose to glabrate
var. divergens
2. Most pedicellate spikelets sterile, 1-6 mm long, without a lemma; sheaths and blades usually glabrous, occasionally pubescent
var. scoparium
1. Lower glumes of the sessile spikelets glabrous or scabrous; pedicels ciliate on 1 edge
var. sanguineum
1. Lower glumes of the sessile spikelets pubescent to hirsute; pedicels ciliate on both edges
var. hirtiflorum
Source FNA vol. 25, p. 669. FNA vol. 25, p. 674.
Parent taxa Poaceae > subfam. Panicoideae > tribe Andropogoneae > Schizachyrium Poaceae > subfam. Panicoideae > tribe Andropogoneae > Schizachyrium
Sibling taxa
S. cirratum, S. littorale, S. maritimum, S. niveum, S. rhizomatum, S. sanguineum, S. spadiceum, S. tenerum
S. cirratum, S. littorale, S. maritimum, S. niveum, S. rhizomatum, S. scoparium, S. spadiceum, S. tenerum
Subordinate taxa
S. scoparium var. divergens, S. scoparium var. scoparium, S. scoparium var. stoloniferum
S. sanguineum var. hirtiflorum, S. sanguineum var. sanguineum
Synonyms Andropogon scoparius
Name authority (Michx.) Nash (Retz.) Alston
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