Spinifex hirsutus

HABIT Perennial; mat forming. Stolons present. Culms 30–90 cm long; woody. Culm-nodes glabrous. Leaf-sheaths pubescent; outer margin hairy. Ligule a fringe of hairs; 2–7 mm long. Leaf-blades flat, or involute; 20–40 cm long; 5–17 mm wide; indurate; stiff; glaucous. Leaf-blade surface pubescent; hairy on both sides. Leaf-blade apex acuminate; pungent.

INFLORESCENCE Dioecious. Synflorescence compound; stellate; 15–30 cm long; with principal spatheoles embracing a compact fascicle of racemes, each subtended by a subsidiary bract. Inflorescence composed of racemes; terminal and axillary; deciduous as a whole (first synflorescence, subsequently racemes); subtended by a spatheole; embraced at base by subtending leaf. Spatheole expanded; lanceolate; 4–8 cm long; scarious.

Racemes 1; single; radiating; unilateral; 7–15(–19) cm long; bearing 1 spikelet (at the base). Rhachis subterete; pubescent on surface, or pilose on surface; terminating in a barren extension; extension subulate (quill-like, spinous); extension 70–190 mm long. Spikelet packing abaxial.

Spikelets appressed; solitary. Fertile spikelets sessile. Male spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; acute, or acuminate; 12–16 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pubescent.

GLUMES Glumes similar; reaching apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of spikelet; chartaceous; without keels; 7–9 -veined. Lower glume surface glabrous, or puberulous. Lower glume apex acuminate. Upper glume lanceolate; 0.9–1 length of spikelet; chartaceous; without keels; 7–9 -veined. Upper glume surface glabrous, or puberulous. Upper glume margins eciliate, or ciliate. Upper glume apex acuminate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; lanceolate; 1 length of spikelet; chartaceous; 5–9 -veined; smooth, or scaberulous; rough on veins; ciliate on margins; acuminate. Fertile florets female. Fertile lemma lanceolate; 11–15 mm long; membranous; much thinner on margins; without keel. Lemma apex acuminate.

FRUIT Disseminule comprising a synflorescence. Secondary disseminule an inflorescence.

MALE Male inflorescence unlike female (racemes bearing 4–8 spikelets); a single raceme (in a compound capitulum). Male spikelets distinct from female; 2 flowered; lanceolate; 8–12 mm long; hairy. Male spikelet glumes 2.

DISTRIBUTION Australasia: Australia. Pacific: southwestern.

NOTES Paniceae. Webster.

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