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.

Yakirra websteri

HABIT Perennial. Culms erect; 25–80 cm long; 2–3 -noded. Lateral branches lacking. Leaf-sheaths longer than adjacent culm internode; without keel. Ligule a fringe of hairs; 0.5 mm long. Leaf-blades 7–12 cm long; 2–5 mm wide. Leaf-blade surface pubescent; with tubercle-based hairs. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 10–20 cm long. Primary panicle branches spreading; 5–10 cm long. Panicle axis pilose; with tubercle-based hairs. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels angular; straight; 2–8 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; 2.5 mm long; 1.5 mm wide; falling entire; readily shedding fertile florets. Rhachilla internodes elongated between glumes. Floret callus evident; winged; with free apical wings; truncate.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 1.5 mm long; 0.66 length of spikelet; membranous; without keels; 3–5 -veined. Lower glume surface scabrous; rough on veins. Lower glume apex acute. Upper glume ovate; 2.5 mm long; 1 length of spikelet; membranous; without keels; 9 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; acuminate. Fertile lemma elliptic; 1.8 mm long; chartaceous; yellow, or light brown; without keel. Lemma margins involute. Lemma apex obtuse. Palea involute; 1 length of lemma; chartaceous.

FRUIT Caryopsis with adherent pericarp; 1.5 mm long.

DISTRIBUTION Australasia: Australia.

NOTES Paniceae. Simon 1995.

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