Sporobolus silveanus

HABIT Perennial; caespitose; clumped densely. Butt sheaths papery; glossy. Culms erect; slender; 90–120 cm long. Culm-internodes antrorsely scabrous. Leaves mostly basal. Leaf-sheaths without keel; glabrous on surface, or pubescent. Ligule a fringe of hairs; 0.1–0.8 mm long. Leaf-blades curved, or flexuous; conduplicate, or involute; 15–30 cm long; 1–2 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 30–40 cm long; 10–12 cm wide; bearing few spikelets. Primary panicle branches ascending.

Spikelets appressed, or ascending; solitary. Fertile spikelets pedicelled. Pedicels 5–8 mm long.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 5–6 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes deciduous; reaching apex of florets. Lower glume lanceolate; 3–4.5 mm long; 0.75 length of upper glume; membranous; purple; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute, or acuminate. Upper glume ovate; 4–6 mm long; 1 length of adjacent fertile lemma; membranous; purple; without keels; 3 -veined. Upper glume lateral veins absent. Upper glume apex acute, or acuminate.

FLORETS Fertile lemma ovate; 5–6 mm long; membranous; without keel; 1 -veined. Lemma apex acute. Palea 1 length of lemma; 2 -veined. Palea keels approximate.

FLOWER Anthers 3–4 mm long; purple.

FRUIT Caryopsis with free soft pericarp; oblong; 2–2.5 mm long. Embryo 0.33 length of caryopsis.

DISTRIBUTION North America: south-central USA and southeast USA.

NOTES Eragrostideae. Gr Tex 1993.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.