Sorghum halepense*

Sorghum halepense* (L.) Pers. Syn.
i. 101 (1805).

Classification. (GPWG 2001) : Subfamily
Panicoideae. Andropogoneae.

Basionym and/or
Replacement Name:
 Holcus
halepensis
L., Sp. Pl. 2: 1047–1048 (1753).

Type of Basionym or
Protologue Information
: Syria:, (HT: ?; ST: LINN-1212.7).

Recent synonyms:
Sorghum miliaceum.

Key references
(books and floras):
[1878] G.Bentham, Flora Australiensis 7 (540),
[1952] C.A.Gardner, Flora of Western Australia 1 Gramineae (317),
[2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia, [2002]
J.Wheeler, N.Marchant & M.Lewington, Flora of the South West (434), [2006]
J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South Australia (533),
[2008] S.W.L.Jacobs, R.D.B.Walley & D.J.B.Wheeler, Grasses of New South
Wales
(373).

Illustrations:
[1984] N.T.Burbidge. rev. S.W.L.Jacobs, Australian Grasses  (243), [2006] J.Jessop, G.R.M.Dashorst,
F.M.James, Grasses of South Australia  (532, fig. 454), [2008] S.W.L.Jacobs,
R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th edn
(373).

Habit. Perennial.
Rhizomes present, elongated. Culms erect or geniculately ascending or
decumbent, 50–300 cm tall, 5–10 mm diam. Mid-culm nodes pubescent. Lateral
branches sparsely branched. Leaves cauline. Ligule an eciliate membrane or a
fringed membrane, a ciliolate membrane, 5 mm long, abaxially glabrous.
Leaf-blades linear or lanceolate, 20–90 cm long, 5–40 mm wide. Leaf-blade
surface smooth.

Inflorescence.
Inflorescence compound, a panicle of rames. Panicle lanceolate or ovate or
pyramidal, 10–55 cm long, 3–25 cm wide.

Spikelets.
Spikelets sessile, 1 in the cluster. Companion spikelets pedicelled, 1 in the
cluster. Companion spikelets developed, containing empty lemmas or male,
4.5–6.5 mm long. Companion spikelet glumes muticous. Fertile spikelets
2-flowered, the lower floret barren (rarely male), the upper fertile,
comprising 1 fertile floret(s), without rachilla extension, elliptic or ovate,
dorsally compressed, 4–6 mm long.

Glumes.
Glumes dissimilar, firmer than fertile lemma. Lower glume elliptic or ovate,
coriaceous, of similar consistency above or much thinner above, without keels
or keeled, 2-keeled, 7–12 -nerved. Lower glume surface glabrous or indumented.
Upper glume ovate, coriaceous, without keels, 7 -nerved. Upper glume surface
glabrous or indumented. Florets. Basal sterile florets 1, barren,
without significant palea. Lemma of lower sterile floret 80 % of length of
spikelet, hyaline, 2 -nerved.

Fertile lemma 2–4 mm
long, 1–3 -nerved. Lemma apex entire or dentate, muticous or awned, 1 -awned.
Median (principal) awn from a sinus, 10–16 mm long overall, with a twisted
column. Palea present or absent. Lodicules present. Anthers 3. Grain 2.5–3 mm
long.

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

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

Western Australia:
Drummond. South Australia: Lake Eyre, Flinders Ranges, Eastern, Eyre
Peninsula, Northern Lofty, Murray, Yorke Peninsula, Southern Lofty, Kangaroo
Island, South-eastern. Queensland: Cook, Burke, North Kennedy, South
Kennedy, Port Curtis, Burnett, Wide Bay, Darling Downs, Moreton. New South
Wales
: North Coast, Central Coast, Northern Tablelands, Central Tablelands,
Southern Tablelands, North-Western Slopes, Central-Western Slopes,
South-Western Slopes, South Far Western Plains. Victoria: Murray Mallee,
Wimmera, Riverina, Volcanic Plain, Eastern Highlands, Gippsland Plain.

Notes. The
forms with awned and unawned spikelets have been formally recognised by some
authors but as awned and unawned spikelets are commonly found in the same
inflorescence, formal recognition is not followed.

Widespread in both tropical
and temperate Australia. Introduced early to Australia as a fodder grass, but
has become an aggressive agricultural weed. Flowers Nov.--May.

 

AVH 2011

   

  

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith