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.

Rytidosperma bipartitum

HABIT Perennial; caespitose. Culms erect; 30–70 cm long; 1 mm diam.; 4 -noded. Leaf-sheaths smooth. Ligule a fringe of hairs. Leaf-blades flat, or involute; 20–30 cm long; 1–2.5 mm wide. Leaf-blade surface glabrous, or hirsute; sparsely hairy.

INFLORESCENCE Inflorescence a panicle.

Panicle open, or contracted; lanceolate, or ovate; 4–12 cm long. Primary panicle branches 2–4 cm long. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 6 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 8–13 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 1 mm long; pilose.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume elliptic; 8–13 mm long; 1 length of upper glume; membranous; without keels; 5–7 -veined. Lower glume primary vein smooth, or scaberulous. Lower glume apex attenuate. Upper glume elliptic; 8–13 mm long; 1–1.5 length of adjacent fertile lemma; membranous; without keels; 5–7 -veined. Upper glume primary vein smooth, or scaberulous. Upper glume apex attenuate.

FLORETS Fertile lemma lanceolate; 8–9 mm long; chartaceous; without keel; 9 -veined. Lemma surface pubescent; with a transverse row of hair tufts. Lemma hairs 4–5 mm long. Lemma apex lobed; 2 -fid; with lobes 5 mm long; incised 0.6 of lemma length; attenuate; awned; 3 -awned. Principal lemma awn from a sinus; curved; reflexed; 7–11 mm long overall; without a column. Lateral lemma awns arising on apex of lobes; 2–3 mm long. Palea lanceolate, or elliptic; 4.5 mm long. Palea keels ciliolate. Palea surface villous; hairy on back and on flanks; hairy below. Palea apex acute. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; fleshy; ciliate. Anthers 3; 1–2 mm long; yellow, or orange.

FRUIT Caryopsis with adherent pericarp; obovoid; 1.75 mm long.

DISTRIBUTION Australasia: Australia.

NOTES Arundineae. Vickery 1993.

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