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.

Triodia irritans

HABIT Perennial; caespitose; clumped densely. Culms 30–100 cm long. Culm-internodes terete. Leaves distichous. Leaf-sheaths longer than adjacent culm internode; without exudate; without keel; indistinctly veined. Ligule a fringe of hairs. Collar glabrous. Leaf-blades aciculate; conduplicate; 8–20 cm long; 1–2 mm wide; coriaceous; stiff; resinous. Leaf-blade apex pungent.

INFLORESCENCE Inflorescence a panicle; exserted, or embraced at base by subtending leaf.

Panicle contracted; linear; 6–15 cm long. Primary panicle branches appressed; simple.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform; 5–15 mm long.

FERTILE SPIKELETS Spikelets comprising 5–10 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 15–20 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pubescent. Floret callus pubescent.

GLUMES Glumes persistent; similar; reaching apex of florets, or shorter than spikelet; thinner than fertile lemma; gaping. Lower glume lanceolate; 10–20 mm long; 1 length of upper glume; scarious; 1-keeled (slightly); 5 -veined. Lower glume apex acute. Upper glume lanceolate; 10–20 mm long; 1.5–1.7 length of adjacent fertile lemma; scarious; 1-keeled (slightly); 5 -veined. Upper glume apex acute.

FLORETS Fertile lemma oblong; 6–12 mm long; coriaceous; without keel; 3(–9) -veined. Lemma midvein ciliate. Lemma lateral veins with distinct primaries but obscure intermediates. Lemma surface scaberulous; pubescent; hairy below. Lemma apex dentate; 2 -fid; obtuse, or acute; awned; 1 -awned. Principal lemma awn from a sinus; 0.5–3 mm long overall. Palea keels ciliolate; adorned above. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; fleshy. Anthers 3; 3–4 mm long.

DISTRIBUTION Australasia: Australia.

NOTES Eragrostideae. Burbidge.

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