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.

Rytidosperma geniculatum

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; slender; 15–45 cm long; 3 -noded. Leaf-sheaths smooth. Ligule a fringe of hairs. Leaf-blades filiform; involute; 7–20 cm long; 1 mm wide. Leaf-blade surface pubescent; with tubercle-based hairs.

INFLORESCENCE Inflorescence a panicle; comprising 3–15 fertile spikelets.

Panicle contracted; ovate; 1–5 cm long; bearing few spikelets. Panicle branches pubescent.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 4–5 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 5–8 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.75 mm long; pubescent.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume ovate; 5–8 mm long; 1 length of upper glume; membranous; without keels; 7 -veined. Lower glume apex acute. Upper glume oblong; 5–8 mm long; 2 length of adjacent fertile lemma; membranous; without keels; 7 -veined. Upper glume apex acute.

FLORETS Fertile lemma oblong; 6–7 mm long; chartaceous; without keel; 9 -veined. Lemma surface pilose; without hair tufts. Lemma apex lobed; 2 -fid; with lobes 4–6 mm long; incised 0.66 of lemma length; acuminate to setaceously attenuate; awned; 1 -awned, or 3 -awned. Principal lemma awn from a sinus; geniculate; 4–6 mm long overall; not or scarcely exserted from spikelet; with a straight or slightly twisted column. Lateral lemma awns arising on apex of lobes; 0–2 mm long. Palea obovate. Palea keels ciliolate. Palea surface pubescent; hairy on back. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; fleshy; ciliate. Anthers 3; 0.5–1 mm long.

FRUIT Caryopsis with adherent pericarp; oblanceolate; 1 mm long; dark brown.

DISTRIBUTION Australasia: Australia and New Zealand.

NOTES Arundineae. Vickery 1993.

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