Common name
Sudan Grass

Derivation
Sorghum Moench, Methodus 207 (1794), nom. cons.; the Indian name for this genus.

drummondii- in honour of Thomas Drummond (c. 1790–1835), Scots-born naturalist and traveller in North America.

Published in
Publ. Field Columb. Mus. Bot. 3: 21 (1903).

Common synonyms
Sorghum sudanense (Piper) Stapf
Sorghum bicolor (L.) Moench subsp. drummondii (Steud.) de Wet

Habit
Annual, culms solitary or tufted (loosely). Culms erect, 150–300 cm tall, 3–6 mm diam., 6–9-noded, with aerial roots from the nodes. Mid-culm nodes pubescent. Lateral branches simple. Leaves cauline. Ligule a fringed membrane, 2 mm long. Leaf-blades 15–50 cm long, 8–12 mm wide.

Inflorescence
Panicle open, ovate or pyramidal, 15–30 cm long, 8–15 cm wide. Primary panicle branches ascending or spreading, 2–5 -nate, moderately divided, 5–15 cm long. Panicle branches flexuous, scaberulous. Rames 1.5–2.5 cm long, bearing 2–5 fertile spikelets on each. Rhachis tough, ciliate on margins. Rhachis hairs 0.5–0.75 mm long. Rame internodes filiform, 2.5–4 mm long. Rame internode tip transverse, cupiliform.

Spikelets
Spikelets appressed, in pairs, one sessile and fertile and the other (companion) spikelet pedicelled. Pedicels filiform, flattened, 2–3.5 mm long, ciliate, with 0.5–0.75 mm long hairs. Companion spikelets developed, male, lanceolate, dorsally compressed, 5.5–8 mm long, shorter than fertile, persistent. Companion spikelet glumes chartaceous, 9–11-nerved, glabrous, acute, muticous. Companion spikelet lemmas enclosed by glumes. Fertile spikelets 2-flowered, comprising 1 fertile floret, lower floret sterile, upper fertile, without rhachilla extension, lanceolate or elliptic or oblong, dorsally compressed, subacute, 6–7.5 mm long, 2–3 mm wide, persistent on plant. Spikelet callus pilose, base obtuse.

Glumes
Glumes dissimilar, with lower wider than upper, firmer than fertile lemma, shiny. Lower glume elliptic, 100% of length of spikelet, coriaceous, much thinner above, yellow or light brown, keel-less except near apex, 11–15-nerved, midnerve scabrous. Lower glume lateral nerves transversely connected at apex or with cross-nerves. Lower glume surface glabrous or puberulous. Lower glume apex acute. Upper glume elliptic, coriaceous, much thinner above, 7-nerved, midnerve scabrous. Upper glume lateral nerves with cross-nerves. Upper glume surface hairy. Upper glume apex acute.

Florets
Basal sterile floret 1, without significant palea. Lemma of lower sterile floret elliptic, 5–6.5 mm long, hyaline, 2-nerved, ciliate on margins, acute. Fertile lemma ovate, 3.5–4.5 mm long, hyaline, 1-nerved. Lemma margins ciliate. Lemma apex dentate, 2-fid, with lobes 0.5–1 mm long, 1-awned. Median (principal) awn from a sinus, geniculate, 10–16 mm long overall, with a twisted column. Column glabrous. Palea absent or minute. Lodicules 2, oblong, fleshy, ciliate, hairy across the apex. Anthers 3, 4 mm long. Stigmas 2, laterally exserted. Grain with adherent pericarp, ellipsoid or obovoid, dorsally compressed, 3.5–4.5 mm long. Hilum punctiform. Endosperm farinose.

Continental Distribution:
Europe, Africa, Temperate Asia, Tropical Asia, Australasia, Pacific, North America, South America.

Australian Distribution:
Western Australia, Queensland, New South Wales.

Western Australia: Dampier. Queensland: Burke, South Kennedy, Leichhardt, Burnett, Wide Bay, Darling Downs, Moreton, Mitchell, Warrego, Maranoa. New South Wales: North Coast, Central Coast, South Coast, Northern Tablelands, Central Tablelands, North-Western Slopes, Central-Western Slopes, South-Western Slopes, North-Western Plains, South-Western Plains.

Classification. (GPWG 2001):
Panicoideae: Andropogoneae

Notes
A forage grass introduced to Australia from the U.S.A. but originally from the Sudan. Flowers Feb.–Apr.