Spinifex sericeus

HABIT Perennial. Rhizomes elongated. Stolons present. Culms decumbent; 30–90 cm long; 2–4 mm diam.; woody; 5–20 -noded. Culm-nodes glabrous. Leaf-sheaths without keel; pubescent; outer margin hairy. Ligule a fringe of hairs; 1.8–4.5 mm long. Collar pubescent. Leaf-blades flat, or involute; 20–40 cm long; 5–17 mm wide; stiff. Leaf-blade surface pubescent. Leaf-blade margins smooth. Leaf-blade apex acuminate.

INFLORESCENCE Dioecious. Synflorescence compound; stellate; 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; scarious.

Racemes 1; single; radiating; unilateral; 12–17 cm long; bearing 1 spikelet (at the base). Rhachis subterete; scabrous on surface; pubescent on surface; terminating in a barren extension; extension subulate (quill-like, spinous); extension 120–170 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; 12–18 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; membranous, or chartaceous; without keels; 7–9 -veined. Lower glume surface glabrous to pubescent. Lower glume apex acuminate. Upper glume lanceolate; 1 length of spikelet; membranous, or chartaceous; without keels; 7–9 -veined. Upper glume surface glabrous to pubescent. 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, or cartilaginous; 5–9 -veined; prominently veined; smooth, or scaberulous; rough on veins; ciliate on margins; acuminate. Fertile florets female. Fertile lemma lanceolate; 11–15 mm long; membranous; without keel. Lemma apex acuminate.

FRUIT Disseminule comprising a synflorescence. Secondary disseminule an inflorescence.

MALE Male inflorescence unlike female (racemes 2–3cm long bearing 5–8 spikelets); a single raceme (in a compound capitulum). Male spikelets distinct from female; 2 flowered; lanceolate; 8–10 mm long; hairy. Male spikelet glumes 2.

DISTRIBUTION Australasia: Australia and New Zealand. Pacific: southwestern.

NOTES Paniceae. Webster 1995.

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