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 thomsonii

HABIT Perennial; caespitose. Rhizomes absent, or short. Butt sheaths herbaceous; not bulbous, or thickened and forming a bulb. Basal innovations intravaginal. Culms 20–45 cm long. Leaf-sheaths glabrous on surface. Leaf-sheath oral hairs ciliate; 1–3 mm long. Ligule a fringe of hairs; 0.3 mm long. Leaf-blades involute; 10–20 cm long; 1–2 mm wide; stiff. Leaf-blade surface glabrous, or pilose. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence a panicle. Peduncle scaberulous above.

Panicle contracted; linear; 3–6.5 cm long. Panicle axis scabrous. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels scabrous.

FERTILE SPIKELETS Spikelets comprising 5–8 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 3.5–9 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 0.5 mm long. Floret callus evident; 0.2–0.3 mm long; pilose.

GLUMES Glumes persistent; similar; shorter than spikelet, or reaching apex of florets, or exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate, or ovate; (3.5–)5–7(–9) mm long; 1 length of upper glume; membranous; without keels; 5(–7) -veined. Lower glume apex acute. Upper glume lanceolate, or ovate; (3.5–)5–7(–9) mm long; 2 length of adjacent fertile lemma; membranous; without keels; 3(–5) -veined. Upper glume apex acute.

FLORETS Fertile lemma oblong; 2.5–3.5 mm long; chartaceous; without keel; 7(–9) -veined. Lemma surface with marginal hair tufts; bearing 4 hair tufts in all. Lemma apex dentate; 2 -fid; incised 0.1 of lemma length; mucronate, or awned; 1 -awned. Principal lemma awn from a sinus; straight; (0.2–)0.5–1(–2.5) mm long overall; without a column. Palea 2.3–3 mm long. Palea keels ciliolate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; fleshy; ciliate. Anthers 3; 0.4–0.7 mm long.

FRUIT Caryopsis with adherent pericarp; 1–1.3 mm long.

DISTRIBUTION Australasia: New Zealand.

NOTES Arundineae. Connor & Edgar 1993.

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