Sporobolus compositus

HABIT Perennial; culms solitary, or caespitose. Rhizomes absent, or elongated; scaly. Culms erect; 60–170 cm long; 1–5 mm diam. Leaf-sheaths glabrous on surface. Ligule a fringe of hairs. Leaf-blades flat, or conduplicate; 10–30 cm long; 1–4 mm wide. Leaf-blade surface glabrous, or pubescent.

INFLORESCENCE Inflorescence a panicle; terminal and axillary; subtended by an inflated leaf-sheath; embraced at base by subtending leaf, or enclosed. Axillary inflorescences enclosed.

Panicle spiciform; linear; dense, or loose; 5–30 cm long; 0.4–1 cm wide. Primary panicle branches 8–35 in number.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 4–6 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes deciduous; shorter than spikelet; shiny. Lower glume lanceolate; 0.5–1 length of upper glume; membranous; mid-green, or purple; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume ovate; 1 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma ovate; 1.4–2 mm long; membranous; without keel; 1 -veined. Lemma apex acute. Palea 1 length of lemma; 2 -veined. Palea keels approximate.

FLOWER Anthers eventually exserted, or retained within floret (when panicle axillary).

FRUIT Caryopsis with free soft pericarp.

DISTRIBUTION North America: eastern Canada, northwest USA, north-central USA, northeast USA, southwest USA, 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.