Eriachne insularis Domin. Biblioth.
Bot. 85: 362 (1915).
Classification. (GPWG 2001) : Subfamily Micrairoideae.
Type of Basionym or
Protologue Information: Australia, Stradbroke Is.: Domin (PR holo,
(books and floras):  D.Sharp & B.K.Simon, AusGrass, Grasses of
Perennial. Culms 50–80 cm tall. Mid-culm nodes glabrous. Lateral branches
branched or fastigiate. Ligule a fringe of hairs. Leaf-blades erect, filiform,
convolute, 5–8 cm long, 1–2 mm wide. Leaf-blade surface smooth, glabrous.
Inflorescence compound, a panicle. Panicle ovate, effuse, 5–10 cm long, 3–7.5
Spikelets pedicelled. Fertile spikelets 2-flowered, both fertile, comprising 2
fertile floret(s), without rachilla extension, ovate, laterally compressed,
3.25–3.5 mm long.
Glumes similar, thinner than fertile lemma. Lower glume ovate, membranous,
without keels, 9–11 -nerved. Lower glume surface glabrous. Lower glume apex
muticous or mucronate. Upper glume ovate, 2.8–3.8 mm long, membranous, without
keels, 9–11 -nerved. Upper glume surface smooth or scabrous, glabrous. Upper
glume apex muticous or mucronate.
Fertile lemma 3–3.5 mm long, without keel. Lemma surface indumented. Lemma apex
muticous or mucronate or awned, 1 -awned. Median (principal) awn 0.5–0.75 mm
long overall. Palea apex entire, muticous. Grain 1.5–1.8 mm long.
Moreton, Port Curtis, Wide Bay, Cook.
The species is recognised by its leafy compact habit, wiry fastigiate culms,
largely glabrous culms and foliage, open panicle with compressed axis and
divided branches, awnless spikelets, glabrous many-nerved glumes, and appressed
hirsute florets subequal to the glumes. Except for its entire, awnless lemma
and palea, E. insularis morphologically resembles plants of E.
pallescens var. gracilis with 2-floreted spikelets.
Qld on mainland and islands near the east coast. In deep sands and sandy loams
on coastal sandhills and dunes. Flowers and fruits chiefly in Dec., Feb., Apr.
(summer and autumn), sometimes also Aug. and Sept. (late-winter and