Trisetum inaequale

HABIT Perennial; caespitose. Culms 30–40 cm long. Leaf-sheaths 1–2 cm long; striately veined; glabrous on surface, or pubescent. Ligule an eciliate membrane; 1 mm long. Leaf-blades filiform; involute; 20–30 cm long; 0.5–1 mm wide. Leaf-blade surface smooth, or scaberulous; rough adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; oblong, or globose; loose; 3–6 cm long. Panicle axis villous. Panicle branches pubescent.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 3–6 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pubescent. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; shiny; gaping. Lower glume lanceolate; 3–3.7 mm long; 0.66 length of upper glume; hyaline; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume elliptic; 4.5–5 mm long; 0.8–1 length of adjacent fertile lemma; hyaline; 1-keeled; 3 -veined. Upper glume primary vein scaberulous. Upper glume lateral veins obscure. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 4–6 mm long; membranous; keeled; 5 -veined. Lemma midvein scaberulous. Lemma surface scaberulous; glabrous. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.75–0.8 way up back of lemma; straight; 1–2 mm long overall. Palea gaping; 3 mm long; 0.75–0.8 length of lemma; hyaline. Palea keels scaberulous. Rhachilla extension 2 mm long; pubescent.

FLOWER Anthers 3. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; fusiform; 1.6–2 mm long; light brown. Hilum punctiform.

DISTRIBUTION Pacific: north-central.

NOTES Aveneae. Wagner 1993.

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