Trisetum bifidum

HABIT Perennial; caespitose; clumped densely. Culms erect; 40–75 cm long; 1–2 mm diam.; 2–4 -noded. Leaf-sheaths loose; glabrous on surface, or pilose. Ligule an eciliate membrane; 0.2–1.5 mm long. Leaf-blades 10–20 cm long; 3–5 mm wide. Leaf-blade surface glabrous, or pilose.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate, or oblong; 10–20 cm long; 2–5 cm wide. Primary panicle branches 2 -nate; 1.5–7 cm long; bearing spikelets almost to the base. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension, or with diminished florets at the apex. Spikelets cuneate; laterally compressed; 6–8 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1.5 mm long; glabrous to pubescent; hairy below. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; shiny; gaping. Lower glume lanceolate; 2–3.5 mm long; 0.4–0.5 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 5–7 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 5–7 mm long; membranous; much thinner on margins; keeled; 5 -veined. Lemma surface scaberulous. Lemma apex dentate; 2 -fid; acuminate; awned; 1 -awned. Principal lemma awn dorsal; arising 0.25 way up back of lemma; geniculate; 6–10 mm long overall; with twisted column. Palea gaping; 3.5–4 mm long; hyaline.

FLOWER Anthers 3; 0.8 mm long. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Asia-temperate: China and eastern Asia. Asia-tropical: Papuasia.

NOTES Aveneae. Koyama 1994.

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