Sporobolus silveanus

Swallen
Common names: Silveus' dropseed
Endemic
Treatment appears in FNA Volume 25. Treatment on page 137.

Plants perennial; cespitose, not rhizomatous. Culms 70-120 cm. Sheaths shiny and indurate basally, glabrous or appressed hairy elsewhere, hairs to 4 mm; ligules 0.2-0.8 mm; blades 15-52 cm long, 1-2.5 mm wide, flat, folded or involute, bluish-green, remaining so well into winter, glabrous on both surfaces, margins scabridulous. Panicles 21-50 cm long, 5-12 (15) cm wide, longer than wide, open, not diffuse, pyramidal to ovate, with few spikelets; lower nodes with 1-2 (3) branches; primary branches 6-20 cm, ascending, spreading 20-50° from the rachis, not capillary, without spikelets on the lower 1/4–1/2; secondary branches appressed to loosely spreading; pulvini glabrous; pedicels 3-8 (14) mm, longer or shorter than the spikelets, appressed, glabrous, scabrous. Spikelets 4.5-7 (7.2) mm, purplish. Glumes subequal to unequal, linear-lanceolate to lanceolate, membranous; lower glumes 3-4.6 mm, 0.6-0.9 times as long as the upper glumes; upper glumes 4-7.2 mm, from slightly shorter to longer than the spikelets; lemmas 4.4-6.5 mm, lanceolate, membranous, glabrous, acuminate to acute; paleas 4.5-6.7 mm, lanceolate, membranous, glabrous; anthers 3, 3.5-5 mm, purplish. Fruits 1.8-2.2 mm, obovoid, laterally flattened, light brownish. 2n = unknown.

Distribution

Okla., Fla., Ga., Tex., La.

Discussion

Sporobolus silveanus is restricted to the southeastern United States. It grows in wet to mesic pine woodlands and adjoining glades and barren openings, and in black-land prairies, at elevations of 5-200 m.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number."-0.9timesaslongastheupperglumes" is not declared as a valid unit of measurement for this property.

... more about "Sporobolus silveanus"
quadrangular +, fusiform +, obovoid +  and ellipsoid +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Paul M. Peterson +, Stephan L. Hatch +  and Alan S. Weakley +
Swallen +
1 (?) +  and 3 (?) +
multiple +, , +  and single +
keeled +  and rounded +
pseudopetiolate +  and branching +
not fused +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
not pseudopetiolate +
bluish-green +
15 cm150 mm <br />0.15 m <br /> (52 cm520 mm <br />0.52 m <br />) +
involute +, folded +  and flat +
0.1 cm1 mm <br />0.001 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
spikelike +
triangular +  and dome--shaped +
sometimes longer +
membranous +
Silveus' dropseed +
70 cm700 mm <br />0.7 m <br /> (120 cm1,200 mm <br />1.2 m <br />) +
not woody +
Okla. +, Fla. +, Ga. +, Tex. +  and La. +
not waisted +
capillary +
pistillate +  and staminate +
sometimes longer +
bisexual +  and fertile +
round +  and compressed +
reduced +
light brownish +
flattened +  and obovoid +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.22 cm2.2 mm <br />0.0022 m <br />) +
shorter or longer +
subtending +
linear-lanceolate +  and lanceolate +
subequal +  and unequal +
membranous +
uncinate +
0 cm0 mm <br />0 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
paniculate +  and racemose +
hollow +  and solid +
not absent +
acuminate +  and acute +
0.44 cm4.4 mm <br />0.0044 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
membranous +
sometimes longer +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
inconspicuous +
0.3 cm3 mm <br />0.003 m <br /> (0.46 cm4.6 mm <br />0.0046 m <br />) +
scabridulous +
concealed +  and prominent +
2 +  and 1 +
lanceolate +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.67 cm6.7 mm <br />0.0067 m <br />) +
membranous +
not diffuse +
21cm +  and 50cm +
longer than wide +
pyramidal +  and ovate +
5 cm50 mm <br />0.05 m <br /> (12 cm120 mm <br />0.12 m <br />) +
14 cm140 mm <br />0.14 m <br /> (?) +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
mucilaginous +
adherent +  and free +
dry +  and fleshy +
spreading;ascending +
not capillary +
6 cm60 mm <br />0.06 m <br /> (20 cm200 mm <br />0.2 m <br />) +
spikelike +
appressed;loosely spreading +
hairy +, appressed +  and glabrous +
rounded +  and laterally compressed +
shorter to longer +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
1 +  and 3 +
compound +  and simple +
2 (?) +  and 3 (?) +
Gramineae +
Sporobolus silveanus +
Sporobolus +
species +
membranous +
0.4 cm4 mm <br />0.004 m <br /> (0.72 cm7.2 mm <br />0.0072 m <br />) +
quadrangular +, fusiform +, obovoid +  and ellipsoid +
7 (?) +  and 13 (?) +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +