Vacoparis laxiflorum (F.M.Bailey)
Spangler. Austral. Syst. Bot. 16(3): 297 . (2003).
Classification. (GPWG 2001) : Subfamily Panicoideae. Andropogoneae.
Replacement Name: Sorghum
laxiflorum F.M. Bailey, Rep. Bellenden-Ker Range 70 (1889).
Type of Basionym or
Protologue Information: HT: F.M. Bailey s.n., 1 Aug 1889, Australia: Queensland:
Cook District: Mulgrave
River (BRI; IT: K).
(books and floras):  D.Sharp & B.K.Simon, AusGrass, Grasses of
Culms erect or geniculately ascending, 100–200 cm tall, 14 -noded. Mid-culm
internodes pruinose. Mid-culm nodes glabrous or pubescent or bearded. Leaves
cauline. Ligule a fringed membrane, a ciliolate membrane, 1–2 mm long.
Leaf-blades 3–16 mm wide. Leaf-blade surface glabrous or indumented.
Inflorescence compound, a panicle of rames. Panicle elliptic, 7–17 cm long, 3–4
cm wide. Rhachis fragile at the nodes.
Spikelets sessile, 1 in the cluster. Companion spikelets pedicelled, 1 in the
cluster. Companion spikelets represented by single glumes or rudimentary,
comprising 2 unequal glumes without lemmas, 4.3–5 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, oblanceolate, dorsally
compressed, 5.3–6.6 mm long.
Glumes dissimilar, firmer than fertile lemma. Lower glume ovate, coriaceous,
without keels, 11 -nerved. Lower glume surface glabrous or indumented. Upper
glume ovate, membranous or coriaceous, without keels, 7 -nerved. Upper glume
surface 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 3–4 mm
long, 3 -nerved. Lemma apex dentate, awned, 1 -awned. Median (principal) awn
from a sinus, 25–43 mm long overall, with a twisted column. Palea absent. Lodicules
present. Anthers 3. Grain 3 mm long.
Distribution: Tropical Asia and Australasia.
Distribution: Northern Territory, Queensland.
Northern Territory: Darwin &
Gulf. Queensland: Burke, Cook,
Leichhardt, Moreton, North Kennedy, Port Curtis, South Kennedy, Wide Bay.
Near-coastal areas of N.T. and northern and central Qld where it occurs on
cracking clays and alluvial soils. Also in Papua New Guinea. Flowers July,