Derivation
Clausospicula Lazarides, Austral. Syst. Bot. 4: 399 (1991); from Latin, clausus (closed) and spicula (spikelet), alluding to the cleistogmaous nature of the spikelet.

extensa- Latin for widespread. Culms widely separated on the rhizome.

Published in
Austral. Syst. Bot. 4: 399 (1991).

Habit
Annual, loosely tufted. Culms 30–45 cm tall, 5–7-noded. Mid-culm internodes elliptical in section. Mid-culm nodes glabrous. Lateral branches sparsely branched. Leaf-sheaths pilose, with tubercle-based hairs. Leaf-sheaths outer margin hairy. Ligule a fringed membrane, 0.3–0.5 mm long. Leaf-blades flat or conduplicate, 30 cm long, 1.4–2.6 mm wide. Leaf-blade surface pilose, with tubercle-based hairs. Leaf-blade margins cartilaginous. Leaf-blade apex acute.

Inflorescence
Inflorescence exserted or embraced at base by subtending leaf. Panicle open, 20 cm long, bearing few spikelets, 8 cm wide. Primary panicle branches 1–3 in number, simple. Rames bearing a triad of spikelets. Rhachis obsolete. Rame-bases filiform, rame bases persistent, extended into an oblong appendage. Rame bases with 4 mm long appendage.

Spikelets
Spikelets in threes. Pedicels filiform, flattened, 5–5.3 mm long, glabrous. Companion spikelets absent or rudimentary, sterile (if present), comprising 2 subequal glumes without lemmas, linear or lanceolate, 5–12 mm long, separately deciduous. Companion spikelet glumes membranous, thinner on margins, 7-nerved, eciliate on margins or ciliate on margins. Fertile spikelets 2-flowered, comprising 1 fertile floret, lower floret sterile, upper fertile, without rhachilla extension, obovate, dorsally compressed, 10 mm long, falling entire, deciduous with accessory branch structures. Spikelet callus cuneate, curved, 3–3.5 mm long, bearded, base pungent, attached obliquely, with linear scar. Spikelet callus hairs dark brown.

Glumes
Glumes dissimilar, firmer than fertile lemma, shiny. Lower glume obovate, coriaceous, much thinner above, dark brown, keel-less except near apex. Lower glume surface convex. Lower glume surface rugose, rough at apex. Lower glume apex rostrate, muticous or mucronate or awned. Lower glume awn 0.5–3 mm long. Upper glume lanceolate or oblong, 100% of length of spikelet, coriaceous. Upper glume apex attenuate, awned. Upper glume awn 14–19 mm long.

Florets
Basal sterile floret 1, without significant palea. Lemma of lower sterile floret elliptic, 4.5–5 mm long, hyaline, 2-nerved, ciliate on margins, truncate or obtuse. Fertile lemma linear, hyaline, 3-nerved. Lemma margins ciliate. Lemma apex attenuate, 1-awned. Median (principal) awn apical, geniculate, 85–105 mm long overall, 45–60 mm long, with a twisted column. Column 40–55 mm long, pubescent. Palea absent or minute. Lodicules 2, oblong or cuneate, 0.4–0.6 mm long, membranous. Anthers 3, 0.5–1.5 mm long. Ovary glabrous. Grain with adherent pericarp, ellipsoid, 5.6 mm long, glabrous, acute. Hilum punctiform.

Continental Distribution:
Australasia.

Australian Distribution:
Northern Territory: Darwin & Gulf.

Classification. (GPWG 2001):
Panicoideae: Andropogoneae

Notes
Endemic to the western Arnhemland region of N.T. Flowers Feb.–May.