Trisetum preslii

HABIT Perennial; caespitose. Culms 10–20 cm long; 1 -noded. Culm-internodes distally pubescent. Culm-nodes pubescent. Leaf-sheaths smooth; glabrous on surface, or pilose. Ligule a ciliolate membrane; 0.5 mm long. Leaf-blades flat, or conduplicate; 2–7 cm long; 2–3 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous, or pubescent.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; oblong; 2.5–5 cm long. Panicle axis pubescent. Panicle branches pubescent.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 6 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pilose. Floret callus pubescent.

GLUMES Glumes persistent; similar; reaching apex of florets; thinner than fertile lemma; shiny; gaping. Lower glume lanceolate; 3.5–5.5 mm long; 0.75 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scabrous; ciliate. Lower glume lateral veins absent, or distinct. Lower glume apex acute. Upper glume lanceolate; 5–6 mm long; 1.2 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous; ciliate. Upper glume apex acute.

FLORETS Fertile lemma oblong; 4.5–5 mm long; membranous; shiny; keeled; 5 -veined. Lemma surface pubescent. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.66 way up back of lemma; geniculate; 3.5–5 mm long overall; with twisted column. Column of lemma awn puberulous; hairy on lower part. Palea gaping; 3.5 mm long; 0.75 length of lemma; hyaline. Palea keels ciliate.

FLOWER Anthers 3; 1 mm long.

FRUIT Caryopsis with adherent pericarp; glabrous. Hilum punctiform.

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.