Ischaemum fragile

Ischaemum fragile R. Br. Prodr. 205(1810).

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

Type of Basionym or
Protologue Information
: Littora Novae Hollandiae intra tropicum, Collected
on Cook's journey by Banks.
T: Australia.

Recent synonyms:
I. baileyi, Digastrium fragile.

Key references
(books and floras):
[1810]. R.Brown, Prodromus (205), [1878]
G.Bentham, Flora Australiensis 7 (522), [1969] E.E.Henty, Manual
New Guinea
(72 as Digastrium), [2002] D.Sharp & B.K.Simon, AusGrass, Grasses
of Australia

Perennial. Culms erect or geniculately ascending, 40–110 cm tall, 3–7 -noded.
Mid-culm nodes glabrous or bearded. Lateral branches simple. Leaf-sheaths
glabrous on surface or hairy. Ligule an eciliate membrane, 1–3.5 mm long.
Leaf-blades 6–33 cm long, 3–7 mm wide. Leaf-blade surface glabrous or

Inflorescence solid, a rame, with ramose branches. Rhachis fragile at the

Spikelets sessile, 1 in the cluster. Companion spikelets pedicelled, 1 in the
cluster. Companion spikelets developed, comprising 2 subequal glumes without
lemmas or containing empty lemmas or male, 2–6 mm long. 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, oblong or ovate, dorsally compressed, 5–7 mm long.

Glumes. Glumes
dissimilar, firmer than fertile lemma, shiny. Lower glume oblong, cartilaginous
or coriaceous, much thinner above, keeled, 2-keeled, winged on keel, winged
narrowly, 5–7 -nerved. Upper glume lanceolate, 6–7 mm long, coriaceous, keeled,
1-keeled, winged on keel, 5–7 -nerved. Upper glume surface glabrous. Upper
glume apex awned. Florets. Basal sterile florets 1, male, with palea.
Lemma of lower sterile floret hyaline or membranous, 3 -nerved.

Fertile lemma 3–4 mm
long, without keel. Lemma apex lobed, awned, 1 -awned. Median (principal) awn
from a sinus, 10–18 mm long overall, with a twisted column. Anthers 3.

: Tropical Asia and Australasia.

: Northern Territory, Queensland.

Northern Territory: Darwin &
Gulf. Queensland: Cook, Moreton, North
Kennedy, Port Curtis, Wide
Bay, South Kennedy.

Notes. In
savannas and open grasslands with seasonal rainfall. Occurs throughout coastal
Qld and NT, extending to New
Guinea. Flowers Apr.--Dec. and Feb.

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