GrassBase - The Online World Grass Flora

Descriptions

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

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

Trisetum tenellum

HABIT Perennial; caespitose. Culms weak; 2–35(–55) cm long. Leaf-sheaths 0.5–2 cm long; smooth, or scaberulous; glabrous on surface to pubescent. Ligule a ciliolate membrane; 0.2–1 mm long; truncate, or obtuse. Leaf-blades 1–12(–18) cm long; 0.3–1.5(–2) mm wide; grey-green. Leaf-blade surface smooth, or scaberulous; rough abaxially, or on both sides; glabrous, or puberulous; hairy adaxially, or abaxially, or on both sides. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence a panicle. Peduncle glabrous to hirsute above.

Panicle spiciform; linear; 0.5–8.5 cm long; 0.5–1.2 cm wide. Panicle axis glabrous, or puberulous. Panicle branches scaberulous; glabrous, or puberulous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; (3.5–)4–5.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pubescent; with 0.8 mm long hairs. Floret callus pubescent. Floret callus hairs 0.2 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet, or reaching apex of florets; thinner than fertile lemma; shiny; gaping. Lower glume elliptic; 0.75–1 length of upper glume; membranous; light green; 1-keeled. Lower glume apex obtuse, or acute. Upper glume elliptic; membranous; light green; 1-keeled. Upper glume apex obtuse, or acute.

FLORETS Fertile lemma elliptic; 3.5–5 mm long; membranous; shiny; keeled; 5 -veined. Lemma surface papillose. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.75 way up back of lemma; straight, or curved; 2–3(–4) mm long overall. Palea gaping; hyaline. Palea keels scaberulous.

FLOWER Lodicules 2; 0.7 mm long. Anthers 3; 0.6–1.3 mm long.

FRUIT Caryopsis with adherent pericarp; 2 mm long.

DISTRIBUTION Australasia: New Zealand.

NOTES Aveneae. Edgar 2000.

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