Vacoparis laxiflorum

Vacoparis laxiflorum (F.M.Bailey)
Spangler. Austral. Syst. Bot. 16(3): 297 . (2003).

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

Basionym and/or
Replacement Name:
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).

Key references
(books and floras):
[2002] D.Sharp & B.K.Simon, AusGrass, Grasses of

Habit. Annual.
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.

: Tropical Asia and Australasia.

: 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,


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