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 duttonianum

HABIT Perennial; caespitose. Culms erect; 40–80 cm long; 1–2 mm diam. Culm-nodes brown; glabrous. Ligule a fringe of hairs; 0.5 mm long. Leaf-blades conduplicate; 10–20 cm long; 2–3.5 mm wide; glaucous. Leaf-blade apex obtuse.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 4–12 cm long; with spikelets clustered towards branch tips. Primary panicle branches 4–8 cm long. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels scabrous.

FERTILE SPIKELETS Spikelets comprising 5–7 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 11–20 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.75–1 mm long; pubescent.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume elliptic; 10–18 mm long; 0.9 length of upper glume; membranous; much thinner on margins; without keels; 7 -veined. Lower glume apex acuminate. Upper glume elliptic; 11–20 mm long; 2 length of adjacent fertile lemma; membranous; with hyaline margins; without keels; 7 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 6–8 mm long; chartaceous; light brown; shiny; without keel; 9 -veined. Lemma surface with 2 transverse rows of hair tufts. Lemma hairs 2–4 mm long. Lemma apex lobed; 2 -fid; with lobes 3–4 mm long; incised 0.5 of lemma length; awned; 3 -awned. Principal lemma awn from a sinus; geniculate; 11–15 mm long overall; with twisted column. Column of lemma awn 4–6 mm long. Lateral lemma awns arising on apex of lobes; ascending, or wrapped around principal; 3–4 mm long. Palea lanceolate, or ovate. Palea keels ciliolate; adorned above. Palea apex dentate; 2 -fid. Apical sterile florets resembling fertile though underdeveloped.

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

FRUIT Caryopsis with adherent pericarp; obovoid; 2.5 mm long. Embryo 0.5 length of caryopsis.

DISTRIBUTION Australasia: Australia.

NOTES Arundineae. Vickery 1993.

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