GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Trisetum lasiorhachis

HABIT Perennial; caespitose; clumped densely. Rhizomes absent, or elongated. Culms (5–)12–60(–85) cm long. Culm-internodes distally pilose. Leaf-sheaths 3–6 cm long; pubescent. Leaf-sheath oral hairs ciliate. Ligule an eciliate membrane, or a ciliolate membrane; 0.3–0.8 mm long; erose. Leaf-blades 5–25 cm long; 1.3–3 mm wide; dark green. Leaf-blade surface scaberulous; rough adaxially; pilose; sparsely hairy; hairy on both sides. Leaf-blade margins ciliate.

INFLORESCENCE Inflorescence a panicle. Peduncle glabrous to pilose above.

Panicle open; lanceolate; (3–)7–14(–21) cm long; 1–3(–5) cm wide; contracted about primary branches. Primary panicle branches bearing spikelets almost to the base. Panicle axis puberulous to pilose. Panicle branches puberulous to pilose.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels puberulous to ciliate.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 5–8 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pilose. Floret callus pubescent. Floret callus hairs 0.5–0.8 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; shiny; gaping. Lower glume oblong; 0.66–0.8 length of upper glume; membranous; light green; 1-keeled. Lower glume apex acuminate. Upper glume elliptic; membranous; light green; 1-keeled. Upper glume apex acute, or acuminate.

FLORETS Fertile lemma elliptic; 5–7.5 mm long; membranous; shiny; keeled; 5 -veined. Lemma surface scaberulous. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5–0.66 way up back of lemma; straight, or curved; 5–9.5 mm long overall. Palea gaping; hyaline. Palea keels scaberulous; adorned above; with 0.9 of their length adorned.

FLOWER Lodicules 2; 1.3 mm long. Anthers 3; 1.8–2.2 mm long.

FRUIT Caryopsis with adherent pericarp; 2.5 mm long.

DISTRIBUTION Australasia: New Zealand.

NOTES Aveneae. Edgar 2000.

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