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rattail smutgrass, smut grass

tussock dropseed

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

30-100 (120) cm.

30-80 cm.

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.

keeled or rounded;

ligules 0.2-0.5 mm;

blades 10-30 cm long, 2-4 mm wide, flat, becoming folded.

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.

15-35 cm long, 0.4-4 cm wide, contracted to rather lax and open;

primary branches appressed to strongly ascending, without spikelets on the lower XA, lower branches much longer than the internodes;

pedicels 0.1-3 mm.

Spikelets

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

1.3-1.8 mm, plumbeous to greenish.

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.

Fruits

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

0.7-0.9 mm, quadrangular, laterally compressed, reddish-brown, truncate.

Lower

glumes 0.4-0.8 mm, acuminate to truncate;

upper glumes 0.7-1 mm, usually less than H as long as the florets, rarely longer, faintly 1-veined, truncate, erose to denticulate;

lemmas 1.2-1.6(1.8) mm, elliptic, glabrous, 1-veined, acute to obtuse;

paleas 1.4-1.8 mm, elliptic;

anthers 2(3), 0.5-0.8 mm.

2n

= 18, 24, 36.

= 12.

Sporobolus indicus

Sporobolus diandrus

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
HI
[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 diandrus is native from India to southeast Asia and Australia. It is not common in North America, being known only from a few counties in Florida, Mississippi, and Texas.

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

Source FNA vol. 25, p. 122. FNA vol. 25, p. 124.
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. domingensis, S. fimbriatus, S. flexuosus, S. floridanus, S. giganteus, 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 S. indicus var. flaccidus
Name authority (L.) R. Br. (Retz.) P. Beauv.
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