Deyeuxia orizabae

HABIT Perennial; caespitose; clumped densely. Culms 100–150 cm long. Ligule an eciliate membrane. Leaf-blades erect; involute; 20–50 cm long; 1–1.5 mm wide; stiff. Leaf-blade surface scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; oblong, or pyramidal; 15–20 cm long. Primary panicle branches 5–10 cm long. Panicle branches capillary; flexuous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 4–6.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pilose. Floret callus hairs 1–1.5 mm long.

GLUMES Glumes persistent; similar; reaching apex of florets; firmer than fertile lemma; gaping. Lower glume lanceolate; 4–6.5 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 4–6.5 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 4–6 mm long; membranous; without keel; 5 -veined. Lemma surface smooth, or scaberulous; glabrous to pubescent. Lemma apex dentate; 2 -fid; muticous, or awned; 1 -awned. Principal lemma awn from a sinus, or dorsal; arising 0.5 way up back of lemma; straight, or geniculate; 0–5 mm long overall; without a column, or with twisted column. Rhachilla extension 2–2.5 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.

NOTES Aveneae. Fl Nov Gal 1994.

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