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 tolucensis

HABIT Perennial; caespitose; clumped densely. Culms erect; 20–40 cm long. Culm-internodes smooth. Leaves mostly basal. Leaf-sheaths smooth; glabrous on surface. Ligule an eciliate membrane; 1 mm long; truncate. Leaf-blades erect; involute; 20–30 cm long; 1–1.5 mm wide. Leaf-blade surface smooth, or scaberulous; rough abaxially; hirsute; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; pyramidal; 10–15 cm long. Primary panicle branches spreading; 3–6 cm long. Panicle branches smooth.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 6 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus bearded. Floret callus hairs 0.33 length of lemma.

GLUMES Glumes persistent; similar; reaching apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume surface asperulous; rough above. Lower glume apex acuminate. Upper glume lanceolate; 6 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume surface asperulous; rough above. Upper glume apex attenuate.

FLORETS Fertile lemma lanceolate; 6 mm long; membranous; without keel; 5 -veined. Lemma surface puberulous; hairy above. Lemma apex awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 6–7 mm long overall; clearly exserted from spikelet; with twisted column. Column of lemma awn hispidulous. Rhachilla extension 1.5 mm long; pilose; with 1–2 mm long hairs.

FLOWER Lodicules 2. Anthers 3. Stigmas 2.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform. Disseminule comprising a floret.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Aveneae. N Amer Fl 1994.

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