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.

Triodia epactia

HABIT Perennial; caespitose; clumped loosely. Stolons absent, or present; with alternating elongated and bunched internodes. Culms 60–200 cm long; with prop roots. Culm-internodes striate. Leaf-sheaths resinous; smooth; glabrous on surface; outer margin hairy. Leaf-sheath oral hairs pubescent to bearded; 1–5 mm long. Ligule a fringe of hairs; 0.5–1.3 mm long. Leaf-blades straight, or curved, or curled, or flexuous; conduplicate; 15–35 cm long; 0.7–1.7 mm wide; coriaceous; stiff; resinous. Leaf-blade surface grooved on either side of midline; grooved abaxially; smooth. Leaf-blade margins glabrous, or tuberculate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; linear; dense; 10–51 cm long; 1.5–3.5 cm wide. Primary panicle branches simple, or sparsely divided; 4–9 cm long. Panicle axis angular. Panicle branches angular; pubescent in axils.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels angular; 1–11 mm long; pubescent.

FERTILE SPIKELETS Spikelets comprising 5–9 fertile florets; with diminished florets at the apex. Spikelets lanceolate; laterally compressed; 9–12 mm long; 3–5 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1 mm long. Floret callus pilose; disarticulating obliquely. Floret callus hairs 1–2.5 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume lanceolate, or oblong; 4.5–11 mm long; 1 length of upper glume; scarious, or cartilaginous; 1-keeled; 3–5 -veined. Lower glume surface asperulous. Lower glume margins eciliate, or ciliate. Lower glume apex acute, or acuminate; muticous, or mucronate. Upper glume lanceolate, or oblong; 4.5–11 mm long; scarious, or cartilaginous; 1-keeled; 3–5 -veined. Upper glume surface asperulous. Upper glume margins eciliate, or ciliate. Upper glume apex acute, or acuminate; muticous, or mucronate.

FLORETS Fertile lemma oblong; 4–10 mm long; indurate; yellow; without keel; 9 -veined. Lemma midvein ciliate. Lemma lateral veins in close groups. Lemma surface hirsute; hairy at base. Lemma margins ciliate. Lemma apex lobed; 3 -fid; with linear lobes and outer lobes winged; with lobes 1.5–5 mm long; incised 0.5 of lemma length; muticous. Palea lanceolate, or elliptic, or oblong; 3–6 mm long; cartilaginous, or indurate; thinner above. Palea surface pilose; hairy on margins. Palea apex acuminate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; cuneate; 0.7 mm long; fleshy. Anthers 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Australasia: Australia.

NOTES Eragrostideae. Lazarides 1996.

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