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rattail smutgrass, smut grass

giant dropseed

Habit Plants perennial; cespitose, with tough fibrous roots, not rhizomatous. Plants perennial; cespitose, not rhizomatous.
Culms

30-100 (120) cm.

100-200 cm, (3)4-10 mm thick near the base.

Sheaths

usually keeled below, glabrous;

ligules 0.2-0.5 mm;

blades (6)10-30(50) cm long, 1-5 mm wide, flat, glabrous on both surfaces.

rounded below, striate, margins hairy distally, apices with conspicuous tufts of hairs, hairs to 2 mm;

ligules 0.5-1.5 mm;

blades 10-50 cm long, (3)4-10(13) mm wide, flat, glabrous on both surfaces, margins whitish, scabridulous.

Panicles

20-35(50) cm long, 0.3-2.2(3) cm wide, contracted, narrow, sometimes included in the uppermost sheath;

primary branches 0.4-2.5(5) cm, appressed or spreading to 40° from the rachis, as long or longer than the adjacent internodes;

secondary branches appressed, spikelet-bearing to near the base;

pulvini glabrous;

pedicels 0.1-1.8 mm, appressed.

all terminal, 25-75 cm long, 1-4 cm wide, spikelike, dense, usually included in the uppermost sheath;

lower nodes with 1-2(3) branches;

primary branches mostly 0.5-6 cm, appressed or spreading to 30° from the rachis, spikelet-bearing to the base;

secondary branches appressed;

pulvini glabrous;

pedicels 0.5-2 mm, appressed.

Spikelets

2-2.6(2.7) mm, plumbeous to light brownish.

2.5-3.5(4) mm, whitish to plumbeous.

Glumes

subequal, ovate or obovate, membranous;

lower glumes 0.5-1 mm, often without midveins;

upper glumes 0.8-1.6 mm, 1/2 - 2/3 as long as the florets, acute to obtuse, entire;

lemmas 1.8-2.6(2.7) mm, ovate, membranous, glabrous, acute or obtuse;

paleas 1.9-2.4 mm, ovate, membranous, glabrous;

anthers 3, 0.5-1.1 mm, white, sometimes purple-tinged.

unequal, narrowly lanceolate, membranous, prominently keeled;

lower glumes 0.6-2 mm;

upper glumes 2-3.5(4) mm, subequal to the lemmas;

lemmas 2.5-3.5(4) mm, linear-lanceolate, membranous, glabrous, acute;

paleas 2.4-3.4(3.8) mm, linear-lanceolate, membranous, glabrous;

anthers 0.6-1 mm, yellowish.

Fruits

1-1.2 mm, quadrangular, laterally compressed, reddish-brown, truncate.

0.8-1.7 mm, ellipsoid, light yellowish-brown, sometimes translucent.

2n

= 18, 24, 36.

= 36.

Sporobolus indicus

Sporobolus giganteus

Distribution
from FNA
AL; AR; CA; FL; GA; IL; KY; LA; MD; MI; MO; MS; NC; NJ; NY; OK; OR; PA; SC; TN; TX; VA; HI; PR; Virgin Islands
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CO; KS; NM; OK; TX; UT
[WildflowerSearch map]
[BONAP county map]
Discussion

Sporobolus indicus is a pantropical species. It commonly grows in disturbed places and open areas such as roadsides, pastures, and lake shores. In the Flora region, it is found on sandy or clay soils and is associated with many plant communities. The spikelets and upper leaves are often covered with hyphomycetous fungi (Bipolaris spp.); hence the common name of "smutgrass".

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

Sporobolus giganteus grows in sand dunes and sandy areas along rivers and roadsides, at elevations from 100-1830 m. Its range extends from the southwestern United States into northern Mexico.

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

Source FNA vol. 25, p. 122. FNA vol. 25, p. 131.
Parent taxa Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Sporobolus Poaceae > subfam. Chloridoideae > tribe Cynodonteae > Sporobolus
Sibling taxa
S. airoides, S. buckleyi, S. clandestinus, S. coahuilensis, S. compositus, S. contractus, S. creber, S. cryptandrus, S. curtissii, S. diandrus, S. domingensis, S. fimbriatus, S. flexuosus, S. floridanus, S. giganteus, S. heterolepis, S. interruptus, S. jacquemontii, S. junceus, S. nealleyi, S. neglectus, S. pinetorum, S. purpurascens, S. pyramidatus, S. silveanus, S. tenuissimus, S. teretifolius, S. texanus, S. vaginiflorus, S. virginicus, S. wrightii
S. airoides, S. buckleyi, S. clandestinus, S. coahuilensis, S. compositus, S. contractus, S. creber, S. cryptandrus, S. curtissii, S. diandrus, S. domingensis, S. fimbriatus, S. flexuosus, S. floridanus, S. heterolepis, S. indicus, S. interruptus, S. jacquemontii, S. junceus, S. nealleyi, S. neglectus, S. pinetorum, S. purpurascens, S. pyramidatus, S. silveanus, S. tenuissimus, S. teretifolius, S. texanus, S. vaginiflorus, S. virginicus, S. wrightii
Synonyms S. poiretii
Name authority (L.) R. Br. Nash
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