Trisetum barbinode

HABIT Perennial. Culms robust; 25–60 cm long; 2–3 -noded. Culm-nodes pubescent. Leaf-sheaths smooth. Ligule a ciliolate membrane; 1–1.5 mm long; truncate. Leaf-blades 2–4 mm wide. Leaf-blade surface scabrous; rough abaxially, or on both sides; glabrous. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence a panicle. Peduncle pubescent above.

Panicle contracted; linear; equilateral, or nodding; 6–15 cm long. Panicle axis pubescent.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 8–10 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pilose. Floret callus pilose. Floret callus hairs 2.3–3.5 mm long.

GLUMES Glumes persistent; similar; reaching apex of florets; thinner than fertile lemma; shiny; gaping. Lower glume lanceolate; 7–8 mm long; 0.75 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume apex acuminate, or setaceously attenuate. Upper glume lanceolate; 8–10 mm long; 1.2 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acuminate, or setaceously attenuate.

FLORETS Fertile lemma oblong; 7–8 mm long; membranous; shiny; keeled; 5 -veined. Lemma surface pubescent. Lemma apex dentate; 2 -fid; awned; 3 -awned. Principal lemma awn dorsal; arising 0.66 way up back of lemma; geniculate; 7–9 mm long overall; with a straight or slightly twisted column. Column of lemma awn pubescent; hairy on lower part. Lateral lemma awns 0.5–1 mm long. Palea gaping; hyaline. Palea apex with excurrent keel veins.

FLOWER Anthers 3; 1–1.5 mm long.

FRUIT Caryopsis with adherent pericarp; 3.5 mm long; glabrous. Hilum punctiform. Endosperm liquid.

DISTRIBUTION South America: southern South America.

NOTES Aveneae. Fl Pat 1995.

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