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 laeve

HABIT Perennial; caespitose. Culms erect; 20–60 cm long; 2–4 -noded. Culm-nodes glabrous. Leaf-sheaths glabrous on surface, or hirsute. Leaf-sheath oral hairs ciliate. Ligule a fringe of hairs. Leaf-blades filiform; involute; 10–20 cm long; 1–1.5 mm wide; stiff. Leaf-blade surface glabrous, or hirsute; with tubercle-based hairs.

INFLORESCENCE Inflorescence a panicle; comprising 5–20 fertile spikelets. Peduncle smooth, or scaberulous above.

Panicle contracted; linear; 3–4 cm long; bearing few spikelets. Primary panicle branches indistinct the panicle almost racemose, or simple.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels pubescent, or ciliate.

FERTILE SPIKELETS Spikelets comprising 4–6 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 11–18 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 1 mm long; pubescent.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma; gaping. Lower glume lanceolate; 11–18 mm long; 1 length of upper glume; membranous; much thinner on margins; without keels; 5–7 -veined. Lower glume apex acuminate. Upper glume lanceolate; 11–18 mm long; 1.1–1.5 length of adjacent fertile lemma; membranous; with hyaline margins; without keels; 3–5 -veined. Upper glume apex acuminate.

FLORETS Fertile florets divergent. Fertile lemma oblong; 10–12 mm long; chartaceous; shiny; without keel; 9 -veined. Lemma surface with basal hair tufts near margin and with a transverse row of hair tufts. Lemma hairs 4–7 mm long. Lemma apex lobed; 2 -fid; with lobes 6–7 mm long; incised 0.6 of lemma length; awned; 3 -awned. Principal lemma awn from a sinus; geniculate; 11–28 mm long overall; with twisted column. Lateral lemma awns arising on apex of lobes; 2–4 mm long. Palea lanceolate, or oblanceolate; 5 mm long. Palea keels ciliolate; adorned above. Palea apex emarginate, or truncate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; fleshy; ciliate. Anthers 3; 1.5–2 mm long; yellow.

FRUIT Caryopsis with adherent pericarp; obovoid; 2.5 mm long.

DISTRIBUTION Australasia: Australia and New Zealand.

NOTES Arundineae. Vickery 1993.

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