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.

Xerochloa barbata

HABIT Perennial. Culms erect, or geniculately ascending; 20–50 cm long; 3–5 -noded. Culm-nodes glabrous. Ligule a fringe of hairs; 0.4–1.8 mm long. Leaf-blades filiform, or linear; flat, or involute; 2.5–13 cm long; 1.5–4 mm wide. Leaf-blade surface smooth.

INFLORESCENCE Synflorescence compound; linear; 3–12 cm long; open; with principal spatheoles embracing a compact fascicle of racemes, each subtended by a subsidiary bract (3–5 racemes). Inflorescence composed of racemes; terminal and axillary; deciduous as a whole; subtended by a spatheole; enclosed. Spatheole elliptic; 1.1–1.3 cm long (subsidiary bracts 6–9mm long); scarious.

Racemes 1; single; unilateral; 0.3–0.8 cm long; bearing few fertile spikelets; bearing 1 fertile spikelets on each. Rhachis flattened; woolly on surface; terminating in a barren extension; extension flattened. Spikelet packing abaxial.

Spikelets sunken; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 5.5–8.5 mm long; falling entire; deciduous with accessory branch structures. Floret callus pilose.

GLUMES Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.4–2.7 mm long; 0.1–0.33 length of spikelet; hyaline, or membranous; without keels; 0–1 -veined. Lower glume lateral veins absent. Lower glume surface glabrous. Lower glume apex truncate, or acute. Upper glume lanceolate; 2.1–5.6 mm long; 0.33–0.66 length of spikelet; membranous; without keels; 3–5 -veined. Upper glume lateral veins distinct (but distinct). Upper glume surface glabrous, or villous. Upper glume margins eciliate, or ciliate. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate; 1 length of spikelet; cartilaginous; much thinner on margins; 3–5 -veined; sulcate; obtuse, or acute. Palea of lower sterile floret membranous (firmer below); 1.1 length of lemma; woolly; adorned on back. Fertile lemma ovate; 5–7.5 mm long; cartilaginous; shiny; without keel; 3 -veined. Lemma margins flat. Lemma apex caudate. Palea ovate; tightly convolute around flower; 1 length of lemma; cartilaginous; 2 -veined; without keels. Palea apex caudate.

FLOWER Anthers 3; 4.5–5 mm long.

DISTRIBUTION Australasia: Australia.

NOTES Paniceae. Webster.

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