Ischaemum tropicum B.K. Simon. Austrobaileya
3: 88 (1989).
Classification. (GPWG 2001) : Subfamily
Panicoideae. Andropogoneae.
Type of Basionym or
Protologue Information: HT: S.T. Blake 17475, 26 Apr 1947, Australia: Northern Territory, Katherine, 150 m (BRI;
IT: CANB, DNA, K, L, MEL, NSW).
Key references
(books and floras): [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of
Australia.
Habit.
Perennial. Rhizomes present, short. Culms erect, 80–120 cm tall. Mid-culm nodes
pubescent. Lateral branches simple. Ligule a fringe of hairs, 2 mm long.
Leaf-blades 8–20 cm long, 2–4 mm wide. Leaf-blade surface glabrous.
Inflorescence.
Inflorescence digitate, with ramose branches. Rhachis fragile at the nodes.
Spikelets.
Spikelets sessile, 1 in the cluster. Companion spikelets pedicelled, 1 in the
cluster. Companion spikelets represented by single glumes or rudimentary or
developed, comprising 2 subequal glumes without lemmas or containing empty
lemmas or male or male with a few bisexual, 2–7 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, elliptic, dorsally compressed,
5–5.5 mm long.
Glumes.
Glumes dissimilar, firmer than fertile lemma. Lower glume elliptic,
chartaceous, keeled, 2-keeled, winged on keel, winged narrowly, 10 -nerved.
Lower glume surface glabrous. Upper glume lanceolate, coriaceous, keeled,
1-keeled, 4 -nerved. Upper glume surface glabrous. Upper glume apex awned. Florets.
Basal sterile florets 1, male, with palea. Lemma of lower sterile floret
membranous.
Fertile lemma 5 mm
long, without keel. Lemma apex lobed, awned, 1 -awned. Median (principal) awn
from a sinus, 12–16 mm long overall, with a twisted column. Palea present.
Anthers 3.
Continental
Distribution: Australasia.
Australian
Distribution: Northern Territory, Queensland.
Northern Territory: Darwin &
Gulf. Queensland:
Cook.
Notes.
Collected from the Katherine and Robins
Falls regions, N.T. and Moa Is., Qld.
Extends to New Guinea.
Flowers Mar.--Apr. and Aug.
