Deyeuxia nomnov3(Calamagrostis vulcanica)

HABIT Perennial; caespitose; clumped densely. Culms erect; 40–80 cm long. Leaf-sheaths longer than adjacent culm internode; smooth; glabrous on surface. Ligule an eciliate membrane; 0.5 mm long. Leaf-blades curved; aciculate; convolute; 20–40 cm long; 2–3 mm wide; coriaceous; stiff. Leaf-blade surface ribbed; smooth, or scaberulous; rough abaxially; pilose; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; pyramidal; 8–14 cm long. Primary panicle branches spreading, or reflexed; 3–7 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 6–7 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus bearded. Floret callus hairs 2 mm long; 0.4 length of lemma.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of upper glume; membranous; 1-keeled; 3–5 -veined. Lower glume apex acuminate. Upper glume lanceolate; 6–7 mm long; 1.2–1.4 length of adjacent fertile lemma; membranous; 1-keeled; 3–5 -veined. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 5 mm long; membranous; much thinner above; without keel; 5 -veined. Lemma lateral veins excurrent. Lemma surface scabrous. Lemma apex dentate; 4 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 10 mm long overall; clearly exserted from spikelet; with twisted column. Column of lemma awn puberulous. Rhachilla extension 2 mm long; pilose; with 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. Swallen 1994.

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