Vacoparis macrospermum (E.D.Garber)
Spangler. Austral. Syst. Bot. 16(3): 297 . (2003).
Classification. (GPWG 2001) : Subfamily Panicoideae. Andropogoneae.
Replacement Name: Sorghum
macrospermum E.D. Garber, Univ. Calif.
Publ. Bot. 23(6): 323 (1950).
Type of Basionym or
Protologue Information: HT: Anonymous s.n., Australia: Northern
Territory: Darwin and Gulf
District; UC-753385, specimen cultivated in 1948 from seed collected by W.
Hartley "near Darwin"
in 1947 (UC (photo, CANB)).
(books and floras):  D.Sharp & B.K.Simon, AusGrass, Grasses of
Culms erect, stature robust to moderate, 180–380 cm tall, 5–10 mm diam.
Mid-culm nodes glabrous or pubescent. Leaves cauline. Ligule a fringed
membrane, a ciliolate membrane, 2.6–5 mm long. Leaf-blades 30–60 cm long, 15–30
mm wide. Leaf-blade surface glabrous or indumented.
Inflorescence compound, a panicle of rames. Panicle ovate, effuse, 15–35 cm
long. Rhachis fragile at the nodes.
Spikelets sessile, 1 in the cluster. Companion spikelets pedicelled, 1 in the
cluster. Basal sterile spikelets absent or well-developed, 0–4 in number.
Companion spikelets represented by single glumes or rudimentary, comprising 2
subequal glumes without lemmas, 6.5–13.5 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, lanceolate, dorsally compressed, 10–11
Glumes dissimilar, firmer than fertile lemma, shiny. Lower glume ovate,
coriaceous, much thinner above, without keels, 15–20 -nerved. Lower glume
surface glabrous. Upper glume ovate, coriaceous, without keels, winged on
margins, 7 -nerved. Upper glume surface scabrous, 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 3.5–4 mm
long, 1 -nerved. Lemma apex dentate, awned, 1 -awned. Median (principal) awn
from a sinus, 30–52 mm long overall, with a twisted column. Palea absent.
Lodicules present. Anthers 3. Grain 5.2–6.3 mm long.
Distribution: Northern Territory.
Northern Territory: Darwin &
Found in a small area of limestone outcrops north-west of Katherine, N.T.
Flowers Feb.--Apr. Map 17.