GrassBase - The Online World Grass Flora


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

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

Deyeuxia divaricata

HABIT Perennial; caespitose; clumped loosely. Rhizomes short. Basal innovations extravaginal. Culms erect, or geniculately ascending; 52–96 cm long. Culm-internodes distally glabrous. Lateral branches lacking. Leaf-sheaths 8–20 cm long; subequal to internodes; glabrous on surface. Ligule a ciliolate membrane; 2–3.6 mm long; entire, or lacerate; obtuse, or acute. Leaf-blades flat, or involute; 15–60 cm long; 1–3 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; loose; 9–16 cm long; 4–10 cm wide. Primary panicle branches ascending, or spreading; 3–6 -nate; whorled at most nodes; 2–8 cm long. Panicle axis scaberulous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1–5 mm long; scaberulous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 3.4–4.3 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent, or pilose. Floret callus hairs 0.2–1 mm long; 0.05–0.25 length of lemma.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 3.4–4.3 mm long; 1 length of upper glume; membranous; much thinner on margins; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex acute, or acuminate. Upper glume lanceolate; 3.4–4.3 mm long; 1.1–1.2 length of adjacent fertile lemma; membranous; with hyaline margins; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume surface asperulous. Upper glume apex acute, or acuminate.

FLORETS Fertile lemma lanceolate; 3.8–4.3 mm long; membranous; without keel; 5 -veined. Lemma surface scaberulous. Lemma apex awned; 1 -awned. Principal lemma awn dorsal; arising 0.66–0.75 way up back of lemma; geniculate; 4–6 mm long overall; with a straight or slightly twisted column. Palea 1 length of lemma; 2 -veined. Palea keels scaberulous. Rhachilla extension 1.6–1.9 mm long; pilose; with 1–1.5 mm long hairs.

FLOWER Lodicules 2; lanceolate; 0.7–0.8 mm long. Anthers 3; 1.8–2.2 mm long; yellow. Stigmas 2. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; fusiform; 1.8–2.5 mm long; light brown. Hilum punctiform. Disseminule comprising a floret.

DISTRIBUTION North America: Mexico.

NOTES Aveneae. Peterson et al 2006.

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