Spinifex longifolius

HABIT Perennial; mat forming. Stolons present. Culms 30–80 cm long; woody. Culm-nodes glabrous. Leaf-sheaths longer than adjacent culm internode; glabrous on surface; outer margin glabrous. Ligule a fringe of hairs; 2.5–3.2 mm long. Leaf-blades flat, or involute; 15–35 cm long; 1.5–4 mm wide; indurate; stiff; glaucous. Leaf-blade surface glabrous. Leaf-blade apex acuminate; pungent.

INFLORESCENCE Dioecious. Synflorescence compound; stellate; 8–20 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; 2–4 cm long; scarious.

Racemes 1; single; radiating; unilateral; 4–12 cm long; bearing 1 spikelet (at the base). Rhachis subterete; glabrous on surface; terminating in a barren extension; extension bristle-like; extension 40–120 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, or elliptic; dorsally compressed; 6–6.5 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes similar; reaching apex of florets; firmer than fertile lemma. Lower glume lanceolate, or elliptic; 1 length of spikelet; chartaceous; without keels; 7–9 -veined. Lower glume apex acute. Upper glume lanceolate, or elliptic; 1 length of spikelet; chartaceous; without keels; 5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; lanceolate, or elliptic; 1 length of spikelet; chartaceous; 5 -veined; smooth, or scaberulous; rough on veins; acute. Fertile florets female. Fertile lemma lanceolate; 5.6–6.3 mm long; membranous; much thinner on margins; without keel. Lemma apex acute.

FLOWER Anthers 3; 3.5–4.1 mm long.

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; 6–7 mm long; glabrous. Male spikelet glumes 2.

DISTRIBUTION Asia-tropical: Malesia and Papuasia. Australasia: Australia.

NOTES Paniceae. Webster.

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