Ischaemum muticum

Ischaemum muticum L. Sp. Pl. 1049 (1753).

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

Type of Basionym or
Protologue Information
: India:,
(LT: LINN-1214.1).

Key references
(books and floras):
[1878] G.Bentham, Flora Australiensis 7 (520),
[1969] E.E.Henty, Manual Grasses New Guinea (116), [2002] D.Sharp
& B.K.Simon, AusGrass, Grasses of Australia.

Habit.
Perennial. Stolons present. Culms prostrate or sprawling, 15–40 cm tall, 2–6 mm
diam. Mid-culm nodes glabrous. Lateral branches simple. Leaf-sheath auricles
present. Ligule an eciliate membrane, 1 mm long. Leaf-blades 2–15 cm long, 4–14
mm wide.

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 developed, containing empty lemmas or male, 6–8 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 or ovate, dorsally compressed, 5–10 mm long.

Glumes.
Glumes dissimilar, firmer than fertile lemma. Lower glume ovate, cartilaginous
or coriaceous, keeled, 2-keeled, winged on keel, winged broadly or moderately
or narrowly, 6–8 -nerved. Lower glume surface glabrous. Upper glume lanceolate,
6–10 mm long, coriaceous, keeled, 1-keeled, winged on keel, 3–5 -nerved. Upper
glume surface glabrous. Florets. Basal sterile florets 1, male, with
palea. Lemma of lower sterile floret 90 % of length of spikelet, hyaline or
membranous, 3 -nerved.

Fertile lemma 5–6 mm
long, without keel, 3 -nerved. Lemma apex lobed, muticous or mucronate or
awned, 1 -awned. Median (principal) awn from a sinus, 1–8 mm long overall.
Anthers 3.

Continental
Distribution
: Temperate Asia, Tropical Asia, Australasia,
and Pacific.

Australian
Distribution
: Queensland, Christmas Is,
Cocos Keeling Is, Ashmore Reef, Coral Sea Is.

Queensland: Cook, North Kennedy.

Notes.
Littoral areas of northern Qld, extending to coasts of tropical Asia. Flowers Feb.--Nov.

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