Panicum bisulcatum Thunb. Nova
Acta Regiae Soc. Sci. Upsal. 7: 141 (1815).
Classification.
(GPWG 2001) : Subfamily Panicoideae. Paniceae.
Type of Basionym or
Protologue Information: ST: Thunberg s.n., 1818, (UPS).
Key references
(books and floras): [1878] G.Bentham, Flora Australiensis 7 (488 as Panicum
melananthum), [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of
Australia, [2008] S.W.L.Jacobs, R.D.B.Walley & D.J.B.Wheeler, Grasses
of New South Wales.
Illustrations:
[2008] S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South
Wales, 4th edn (314).
Habit. Annual.
Rhizomes absent. Stolons present. Culms decumbent, 20–80 cm tall, compressible
or firm, 3–10 -noded. Mid-culm internodes glabrous. Mid-culm nodes glabrous.
Lateral branches sparsely branched or branched. Leaf-sheaths glabrous on
surface. Leaf-sheath auricles absent. Ligule an eciliate membrane or a fringed membrane,
a ciliolate membrane, 0.5–0.75 mm long. Leaf-blades linear, 2–25 cm long, 4–13
mm wide. Leaf-blade surface smooth or scaberulous.
Inflorescence.
Inflorescence compound, a panicle. Panicle ovate, 10–20 cm long, with spikelets
clustered towards branch tips.
Spikelets.
Spikelets pedicelled. 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
elliptic, dorsally compressed, 2.2–3 mm long. Rhachilla internodes brief up to
lowest fertile floret.
Glumes. Glumes
thinner than fertile lemma. Lower glume ovate, membranous, without keels, 1–5
-nerved. Lower glume apex muticous. Upper glume elliptic, 2.1–2.6 mm long, membranous,
without keels, 5(–7) -nerved. Florets. Basal sterile florets 1, barren,
without significant palea. Lemma of lower sterile floret 100 % of length of
spikelet, membranous, 3–5 -nerved, muticous.
Fertile lemma 2–2.5 mm
long, without keel. Lemma apex muticous. Anthers 3.
Continental
Distribution: Temperate Asia, Tropical Asia, and Australasia.
Australian
Distribution: Queensland, New South Wales, Victoria (*).
Queensland:
Wide Bay, Darling Downs, Moreton. New South Wales: North Coast, Central
Coast, North-Western Slopes. Victoria: Eastern Highlands, Midlands,
Riverina.
Notes.
Diagnostic features of the species include the absence of a lower palea, the
relative length of the lower glume, and the obscure nerves on the upper lemma.
Introduced.Occurs in
Japan, China and India and in the SE coastal region of Australia. In tropical
heaths, tropical and subtropical wet sclerophyll forests, temperate wet
sclerophyll forests, and dry sclerophyll forests. Probably introduced. Flowers
Mar.-June.
