Common name
Annual Sorghum
Annual Canegrass
Black Soil Canegrass
Downs Sorghum

Derivation
Sarga Ewart, Proc. Roy. Soc. Victoria ser. 2, 23: 296 (1911) meaning obscure, origin not given by author but possibly alluding to being intermediate between Agrostis and Stipa.

timorense- denoting origin, from Timor.

Published in
Austal. Syst. Bot. in press.

Common synonyms
Sorghum amplum Lazarides
Sorghum australiense Garber & Snyder
Sorghum brachypodum Lazarides
Sorghum bulbosum Lazarides
Sorghum ecarinatum Lazarides
Sorghum matarankense Garber & Snyder
Sorghum stipoideum (Ewart & J.White) C.A.Gardner & C.E.Hubb.
Sorghum timorense (Kunth) Buse

Habit
Annual. Basal leaf sheaths glabrous or pubescent. Culms erect or geniculately ascending, 30–400 cm tall, 2.6–13 mm diam., 3–9-noded, without nodal roots or with prop roots or with aerial roots from the nodes. Mid-culm internodes pruinose or glabrous. Mid-culm nodes glabrous or pubescent or bearded. Lateral branches simple or sparsely branched. Leaf-sheaths glabrous on surface or puberulous. Ligule an eciliate or a fringed membrane, 1.3–5.8 mm long. Leaf-blades straight or curled, 30–60 cm long, 5–70 mm wide. Leaf-blade surface glabrous or pubescent or pilose or hispid.

Inflorescence
Panicle open, dense or loose, 11–40 cm long, 4–6 cm wide. Primary panicle branches 1–15 -nate, simple or sparsely divided or moderately divided, 2–11 cm long. Panicle axis terete or angular, smooth or scaberulous or scabrous. Panicle branches angular or flat, smooth or scabrous, rough distally, with scattered hairs or pilose or villous, hairy at tip, glabrous in axils or pubescent in axils or bearded in axils, with prominent pulvini. Rames 1.4–5.3 cm long, bearing a triad of spikelets or a few fertile spikelets, bearing 2–10 fertile spikelets on each. Rhachis evident or obsolete, tough or fragile at the nodes, ciliate on margins. Rame internodes linear, 5–6 mm long. Rame internode tip oblique.

Spikelets
Spikelets in pairs, one sessile and fertile and the other (companion) spikelet pedicelled or in threes. Pedicels filiform, flattened, 5–9 mm long, ciliate, with white or tawny hairs. Companion spikelets developed, containing empty lemmas or male, lanceolate, dorsally compressed, 4.5–18 mm long, shorter to longer than fertile, persistent or separately deciduous. Companion spikelet callus square, 1 mm long. Companion spikelet glumes membranous or chartaceous or cartilaginous, 7–10-nerved, glabrous or puberulous or pubescent or pilose, eciliate or ciliate on margins, emarginate or obtuse or acute or acuminate or setaceously acuminate, muticous or mucronate or one glume awned. Companion spikelet glumes with 0–2.3 mm long awn. Companion spikelet lemmas enclosed by glumes, 8.5–10 mm long. Fertile spikelets 2-flowered, comprising 1 fertile floret, lower floret sterile, upper fertile, without rhachilla extension, linear or lanceolate or elliptic or oblong or obovate, dorsally compressed, 6–18 mm long, falling entire, deciduous with accessory branch structures. Spikelet callus brief or square or cuneate, straight or curved, 0.3–10 mm long, pilose, base obtuse or acute or pungent. Spikelet callus hairs tawny.

Glumes
Glumes dissimilar, with lower wider than upper, firmer than fertile lemma, dull or shiny. Lower glume ovate, gibbous, 100% of length of spikelet, cartilaginous or coriaceous or indurate, much thinner above, 2–keeled, 7–11-nerved. Lower glume lateral nerves without connecting nerves or with cross-nerves. Lower glume surface asperulous, rough above, glabrous or puberulous or pubescent or pilose or hirsute, with simple or tubercle-based hairs. Lower glume margins eciliate or ciliate. Lower glume hairs yellow or dark brown. Lower glume hairs 3–4 mm long. Lower glume apex dentate or lobed, 2–3-fid, obtuse or acute or rostrate, muticous or mucronate. Upper glume ovate, cartilaginous or coriaceous or indurate, much thinner above, 5–9-nerved. Upper glume surface asperulous, rough above, glabrous or puberulous or pubescent or pilose or hirsute, with simple or tubercle-based hairs. Upper glume margins eciliate or ciliate. Upper glume hairs tawny. Upper glume apex obtuse or acuminate or setaceously acuminate.

Florets
Basal sterile floret 1, without significant palea. Lemma of lower sterile floret lanceolate, 4.5–10 mm long, hyaline, 2-nerved, acute. Fertile lemma oblong, hyaline, 1-nerved. Lemma apex dentate or lobed, 2-fid, 1-awned. Median (principal) awn from a sinus, geniculate, 30-155 mm long overall, with a twisted column. Column glabrous or ciliate. Palea absent or minute. Lodicules 2, oblong, 0.5–0.9 mm long, fleshy, smooth or ciliate. Anthers 3, 2.5–6 mm long, yellow or orange. Stigmas 2. Ovary glabrous. Grain with adherent pericarp, fusiform or oblong or obovoid, terete or dorsally compressed, 2–6 mm long, glabrous, truncate or obtuse.

Continental Distribution:
Australasia.

Australian Distribution:
Western Australia, Northern Territory, Queensland.

Western Australia: Gardner, Hall, Dampier, Canning, Fortescue. Northern Territory: Darwin & Gulf, Victoria River, Barkly Tableland, Central Australia North. Queensland: Cook, Burke.

Classification. (GPWG 2001):
Panicoideae: Andropogoneae

Notes:
Native.