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.

Psammagrostis

HABIT Annual. Culms decumbent, or prostrate; 4–35 cm long. Ligule a fringe of hairs.

INFLORESCENCE Inflorescence composed of racemes, or comprising only a few spikelets; terminal and axillary; deciduous as a whole; subtended by a spatheole; embraced at base by subtending leaf. Spatheole lanceolate; herbaceous. Peduncle widened at apex; disarticulating.

Racemes single; unilateral; bearing 1 spikelet, or few fertile spikelets; bearing 1–3 fertile spikelets on each. Rhachis flattened.

Spikelets solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 3–7 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 4–8.5 mm long; falling entire; deciduous with accessory branch structures. Rhachilla internodes definite.

GLUMES Glumes shorter than spikelet. Lower glume lanceolate; 0.9–1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface without pits. Lower glume apex acute. Upper glume ovate; 1.1–1.3 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma oblong; membranous; keeled; wingless; 3 -veined. Lemma lateral veins ribbed. Lemma surface unwrinkled; without grooves. Lemma apex obtuse; mucronate. Palea 1 length of lemma; 2 -veined. Palea keels scaberulous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3.

FRUIT Caryopsis with free soft pericarp; oblong; trigonous. Embryo 0.33 length of caryopsis. Hilum punctiform.

DISTRIBUTION Australasia.

Please cite this publication as detailed in How to Cite Version: 27th January 2014.