Dichanthium setosum

HABIT Perennial; caespitose. Culms erect; 30–70 cm long; 2–4 -noded. Culm-internodes channelled. Culm-nodes bearded. Lateral branches lacking. Leaf-sheaths glabrous on surface. Ligule a ciliolate membrane; 0.5–0.75 mm long; truncate. Leaf-blades 7–15 cm long; 2–3.5 mm wide. Leaf-blade surface scaberulous, or scabrous; glabrous, or pilose; with tubercle-based hairs. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1–2(–3); single, or paired; 3.5–8 cm long. Rhachis fragile at the nodes; subterete; ciliate on margins. Rhachis hairs lengthening towards internode tip; 1–2.5 mm long. Rhachis internodes linear; 2 mm long.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; 2 mm long; without a translucent median line; ciliate; hairy all along but hairs longer above; with 1–2.5 mm long hairs.

STERILE SPIKELETS Basal sterile spikelets well-developed; 2–4 in number; male; smaller than fertile. Basal sterile spikelet lemmas awnless.

Companion sterile spikelets well-developed; male; elliptic; 5–5.5 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes 9 -veined; villous. Companion sterile spikelet lemmas enclosed by glumes; 0.5–2.7 mm long; dentate; 1-awned; with 0.5–6 mm long awn.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 5–6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base obtuse; attached transversely. Spikelet callus hairs 0.5–0.9 mm long.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 1 length of spikelet; chartaceous; much thinner above; purple; without keels; keel-less except near apex; 8–9 -veined. Lower glume surface tuberculate (along fringe); pilose; hairy generally; with a transverse fringe of hair. Lower glume margins ciliate. Lower glume hairs 2–3.5 mm long. Lower glume apex truncate, or obtuse. Upper glume lanceolate; 1-keeled; 3 -veined. Upper glume surface scabrous; rough on veins.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret ovate; 2 mm long; hyaline. Fertile lemma linear; hyaline; without keel; 1 -veined. Lemma apex entire; awned; 1 -awned. Principal lemma awn apical; geniculate; 25 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3; 2–2.2 mm long.

FRUIT Caryopsis with adherent pericarp; obovoid; 3 mm long.

DISTRIBUTION Australasia: Australia.

NOTES Andropogoneae. Fl NSW 1993.

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