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.

Thaumastochloa brassii

HABIT Annual. Culms 7–35 cm long; 10–15 -noded. Leaf-sheaths glabrous on surface, or pilose. Ligule a ciliolate membrane. Leaf-blades flat, or involute; 1–3 cm long; 3 mm wide. Leaf-blade surface glabrous, or pilose; sparsely hairy.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary; not deciduous as a whole, or deciduous as a whole; subtended by a spatheole; embraced at base by subtending leaf. Spatheole linear. Peduncle nodding; 0.8–6 cm long; retrorsely scabrous above; glabrous; widened at apex; disarticulating; disarticulating above uppermost sheath; base pungent.

Racemes 1; single; unilateral; 0.3–0.8 cm long; bearing few fertile spikelets; bearing 1(–3) fertile spikelets on each. Rhachis tough, or fragile but the lowest internode fused to peduncle; subcylindrical and excavated; 0.8–1 mm wide; glabrous on surface; terminating in a sterile spikelet. Spikelet packing abaxial; regular; 1 -rowed. Rhachis internodes oblong; 3–4 mm long. Rhachis internode tip transverse; crateriform.

Spikelets sunken; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels fused to internode; united wholly.

STERILE SPIKELETS Companion sterile spikelets represented by barren pedicels.

Apical sterile spikelets rudimentary.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 2–2.7 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus glabrous; base truncate; with central peg; attached transversely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; indurate; 2-keeled; keeled laterally; 7 -veined. Lower glume surface flat; rugose. Lower glume apex obtuse. Upper glume elliptic; coriaceous; with hyaline margins; without keels.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret hyaline. Fertile lemma hyaline; without keel; 2 -veined. Palea hyaline.

FLOWER Anthers 3; 0.6–0.7 mm long.

DISTRIBUTION Australasia: Australia.

NOTES Andropogoneae. Koning.

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