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Barbon de Gerard, big bluestem

broom sedge, broomsedge bluestem

Habit Plants often forming large clumps, rhizomes, if present, with internodes shorter than 2 cm. Plants cespitose, dense and cylindrical to obpyramidal above.
Culms

1-3 m, often glaucous.

40-210 cm;

internodes glaucous or not;

branches erect to ascending, usually straight, sometimes arching.

Sheaths

glabrous or pilose;

ligules 0.4-2.5 mm;

blades 5-50 cm long, (2)5-10 mm wide, usually pilose adaxially, at least near the collar.

usually smooth, rarely somewhat scabrous;

ligules 0.2-1 mm, ciliate, cilia 0.2-1.3 mm;

blades 11-52 cm long, 1.7-6.5 mm wide, smooth and glabrous or sparsely to densely pubescent with spreading hairs.

Inflorescence units

usually only terminal;

peduncles with 2-6(10) rames;

rames 5-11 cm, exserted at maturity, usually purplish, sometimes yellowish;

internodes sparsely to densely pubescent, hairs 2.2-4.2 mm, usually white, rarely yellowish.

6-195 per culm; subtending sheaths (2.1)3.1-4.6(6.7) cm long, (1.7)3-3.8(5.6) mm wide;

peduncles usually (1)4-6(30) mm, with 2-7 rames;

rames (0.5)1.7-2.8(4.4) cm, sometimes exerted at maturity, pubescence sparse basally and increasing in density distally within each internode.

Sessile

spikelets 5-11 mm, scabrous;

awns 8-25 mm;

anthers 3, 2.5-4.5 mm.

spikelets (2.6)3.5-3.8(4.7) mm;

callus hairs 1-3 mm;

keels of lower glume usually smooth below midlength, scabrous distally;

awns 6-21 mm;

anthers 1(3), 0.6-1.5 mm, yellow or purple.

Pedicellate

spikelets 3.5-12 mm, usually well-developed and staminate.

spikelets vestigial to absent.

2n

= 20, 40, 60 (usually), 70, 80.

= 20.

Andropogon gerardii

Andropogon virginicus

Distribution
from FNA
AL; AR; AZ; CO; CT; DC; DE; FL; GA; IA; 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; WI; WV; WY; MB; ON; QC; SK
[WildflowerSearch map]
from FNA
AL; AR; CA; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MI; MO; MS; NC; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; WV; HI; PR; ON
[WildflowerSearch map]
[BONAP county map]
Discussion

Andropogon gerardii grows in prairies, meadows, and generally dry soils. It is a widespread species, extending from southern Canada to Mexico, and was once dominant over much of its range. It is frequently planted for erosion control, restoration, or as an ornamental; the records from Washington and central Montana reflect such plantings. It hybridizes with A. ballii, the two sometimes being treated as conspecific subspecies.

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

Andropogon virginicus is native from the southeastern United States to northern South America, but has become established outide its native range in California, Hawaii, Japan, and Australia. Three varieties are recognized, two of which contain morphologically distinct variants. Andropogon virginicus hybridizes with A. glomeratus and A. longiberbis (Campbell 1986).

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

Key
1. Leaves bluish-green, more or less strongly glaucous
var. glaucus
1. Leaves green, sometimes somewhat glaucous.
→ 2
2. Sheaths subtending the inflorescence units (1.7)2.4-3.1(4) mm wide; inflorescences units usually with 2 rames; rames (1.3)1.5-2.3(3) cm long; peduncles (1) 4-9 (30) mm long
var. decipiens
2. Sheaths subtending the inflorescences units (2.2)3.3-4.4(5.6) mm wide; inflorescence units with 2-5(7) rames; rames (0.5)1.9-3.3(4.4) cm long; peduncles (2)3-6(12) mm long
var. virginicus
Source FNA vol. 25, p. 653. FNA vol. 25, p. 659.
Parent taxa Poaceae > subfam. Panicoideae > tribe Andropogoneae > Andropogon > sect. Andropogon Poaceae > subfam. Panicoideae > tribe Andropogoneae > Andropogon > sect. Leptopogon
Sibling taxa
A. arctatus, A. bicornis, A. brachystachyus, A. floridanus, A. glomeratus, A. gracilis, A. gyrans, A. hallii, A. liebmannii, A. longiberbis, A. ternarius, A. tracyi, A. virginicus
A. arctatus, A. bicornis, A. brachystachyus, A. floridanus, A. gerardii, A. glomeratus, A. gracilis, A. gyrans, A. hallii, A. liebmannii, A. longiberbis, A. ternarius, A. tracyi
Subordinate taxa
A. virginicus var. decipiens, A. virginicus var. glaucus, A. virginicus var. virginicus
Synonyms A. provincialis, A. furcatus
Name authority Vitman L.
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