Sporobolus tenuissimus

(Mart, ex Schrank) Kuntze
Common names: Tropical dropseed
Introduced
Treatment appears in FNA Volume 25. Treatment on page 118.

Plants annual; tufted. Culms 30-100 cm. Sheaths glabrous, including the apices; ligules 0.2-0.3 mm; blades 5-23 cm long, 2-4 mm wide, flat or folded, glabrous on both surfaces, margins glabrous. Panicles (8) 15-30 cm long, 3.5-8 cm wide, open, diffuse, cylindrical; lower nodes with 1-2 (3) branches; primary branches 0.6-5 cm, capillary, spreading 30-70° from the rachises, without spikelets on the lower 1/2; secondary branches spreading; pedicels 0.5-5 mm. Spikelets 0.7-1.1 mm, plumbeous to purplish. Glumes unequal, obovate to ovate, membranous; lower glumes 0.1-0.4 mm, occasionally absent; upper glumes 0.2-0.5 mm; lemmas 0.7-1.1 mm, elliptic, membranous, glabrous, acute to obtuse; paleas 0.7-1.1 mm, elliptic, membranous; anthers 0.2-0.3 mm, yellowish. Fruits 0.4-0.7 mm, pyriform or quadroid, somewhat laterally flattened, light brownish to whitish. 2n = 12.

Distribution

Puerto Rico, S.C., Fla., Virgin Islands

Discussion

Sporobolus tenuissimus is native to the Western Hemisphere, and introduced to Africa and Asia. Its native distribution in the Americas is tropical, extending from southern Mexico to Brazil and Paraguay. It has been found at a few locations in the southeastern United States, at 0-100 m. It grows in disturbed areas, often occurring as a weed in gardens and cultivated fields.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Sporobolus tenuissimus"
quadrangular +, fusiform +, obovoid +  and ellipsoid +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
Paul M. Peterson +, Stephan L. Hatch +  and Alan S. Weakley +
(Mart, ex Schrank) Kuntze +
1 (?) +  and 3 (?) +
multiple +, , +  and single +
keeled +  and rounded +
pseudopetiolate +  and branching +
not fused +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
not pseudopetiolate +
5 cm50 mm <br />0.05 m <br /> (23 cm230 mm <br />0.23 m <br />) +
folded +  and flat +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
spikelike +
triangular +  and dome--shaped +
sometimes longer +
membranous +
Tropical dropseed +
30 cm300 mm <br />0.3 m <br /> (100 cm1,000 mm <br />1 m <br />) +
not woody +
Puerto Rico +, S.C. +, Fla. +  and Virgin Islands +
not waisted +
capillary +
pistillate +  and staminate +
sometimes longer +
bisexual +  and fertile +
round +  and compressed +
reduced +
light brownish +  and whitish +
flattened +, quadroid +  and pyriform +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
shorter or longer +
subtending +
obovate +  and ovate +
unequal +
membranous +
uncinate +
paniculate +  and racemose +
hollow +  and solid +
not absent +
acute +  and obtuse +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
membranous +
sometimes longer +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
inconspicuous +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
concealed +  and prominent +
2 +  and 1 +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
membranous +
15cm +  and 30cm +
cylindrical +
3.5 cm35 mm <br />0.035 m <br /> (8 cm80 mm <br />0.08 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
mucilaginous +
adherent +  and free +
dry +  and fleshy +
0.6 cm6 mm <br />0.006 m <br /> (5 cm50 mm <br />0.05 m <br />) +
spikelike +
Introduced +
plumbeous +  and purplish +
1 +  and 60 +
rounded +  and laterally compressed +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
1 +  and 3 +
compound +  and simple +
2 (?) +  and 3 (?) +
Gramineae +
Sporobolus tenuissimus +
Sporobolus +
species +
membranous +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
quadrangular +, fusiform +, obovoid +  and ellipsoid +
7 (?) +  and 13 (?) +
stoloniferous +  and rhizomatous +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +