GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Sporobolus contractus

HABIT Perennial; caespitose. Culms erect; of moderate stature; 40–110 cm long; 2–3.5 mm diam. Culm-internodes eglandular, or glandular. Culm-nodes constricted; glabrous. Leaf-sheaths without keel; glabrous on surface; outer margin glabrous, or hairy. Ligule a fringe of hairs; 0.5–1 mm long. Collar pilose. Leaf-blades flat, or involute; 4–35 cm long; 3–8 mm wide. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle; embraced at base by subtending leaf.

Panicle spiciform; linear; 15–50 cm long; 0.5–0.7 cm wide.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 2.5–3.2 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes deciduous; shorter than spikelet. Lower glume lanceolate; 1–2 mm long; 0.75 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume ovate; 2–2.7 mm long; 0.75–1 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma ovate; 2.4–3.2 mm long; membranous; without keel; 1 -veined. Lemma apex acute. Palea 0.9 length of lemma; 2 -veined. Palea keels approximate.

FRUIT Caryopsis with free soft pericarp; 1 mm long; light brown. Embryo 0.5 length of caryopsis.

DISTRIBUTION North America: northwest USA, southwest USA, south-central USA, and Mexico.

NOTES Eragrostideae. Gr Tex 1993.

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