Sorghum nitidum

Sorghum nitidum (Vahl) Pers. Syn.
1: 101 (1805).

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

Basionym and/or
Replacement Name:
 Holcus nitidus
Vahl, Symb. Bot. 2: 102 (1791).

Type of Basionym or
Protologue Information
: HT: Hab. in India orientalis (C?).

Key references
(books and floras):
[1810]. R.Brown, Prodromus (199 as Holcus
), [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia.

Perennial. Rhizomes absent. Culms erect, 100–200 cm tall, wiry, 4–6 -noded.
Mid-culm nodes bearded. Lateral branches simple or sparsely branched. Ligule an
eciliate membrane or a fringed membrane, 2 mm long. Leaf-blades 30–60 cm long,
4–15 mm wide. Leaf-blade surface glabrous or indumented.

Inflorescence compound, a panicle of rames. Panicle lanceolate, dense or loose,
10–30 cm long. Rhachis fragile at the nodes.

Spikelets sessile, 1 in the cluster. Companion spikelets pedicelled, 1 in the
cluster. Companion spikelets developed, comprising 2 subequal glumes without
lemmas or male, 3–6 mm long. Companion spikelet glumes muticous. Fertile
spikelets 2-flowered, the lower floret barren (rarely male), the upper fertile,
comprising 1 basal sterile florets, comprising 1 fertile floret(s), without
rachilla extension, lanceolate or ovate, dorsally compressed, 3–5.5 mm long.

Glumes. Glumes
dissimilar, firmer than fertile lemma, shiny. Lower glume ovate, coriaceous,
much thinner above, without keels. Lower glume surface indumented. Upper glume
ovate, coriaceous, without keels. Upper glume surface indumented. Florets.
Basal sterile florets 1, barren, without significant palea. Lemma of lower
sterile floret hyaline, 2 -nerved.

Fertile lemma 3 mm
long, 1 -nerved. Lemma apex dentate or lobed, muticous or awned, 1 -awned.
Median (principal) awn from a sinus, 7–17 mm long overall, with a twisted
column. Palea absent. Lodicules present. Anthers 3. Grain 2.3 mm long.

: Temperate Asia, Tropical Asia, Australasia, and Pacific.

: Queensland.

Burnett, Cook, Leichhardt, North Kennedy, Port Curtis, South Kennedy, Wide Bay.

Notes. There
are two forms. The awned and awnless forms are recognised as separate taxa as
the spikelets are usually uniformly awned or unawned in the same inflorescence.
There are only two records of specimens of spikelets having awned and awnless
spikelets in the same panicle.

Found in eastern Qld
on grey and brown loams and sands and in disturbed habitats. Also in tropical
Asia and Japan. Flowers Dec.--July.

f. nitidum, f.aristatum.

Spikelets awnless         S. nitidum forma nitidum

Spikelets awned              S. nitidum
forma aristatum     


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