Ischaemum barbatum

Ischaemum barbatum Retz. Observ. Bot. 6: 35 (1791).

(GPWG 2001) : Subfamily Panicoideae. Andropogoneae.

Type of Basionym or
Protologue Information
: Indonesia:
Java:, D. Wennerberg ?.

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

Perennial. Culms erect or geniculately ascending, 60–160 cm tall. Mid-culm
nodes glabrous. Lateral branches simple. Ligule an eciliate membrane, 2–3.5 mm
long. Leaf-blades 7–20 cm long, 4–10 mm wide.

Inflorescence digitate, with ramose branches. Rhachis fragile at the nodes.

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, asymmetrical, 4–6 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 oblong,
dorsally compressed, 5.5–8 mm long.

Glumes. Glumes
dissimilar, firmer than fertile lemma. Lower glume oblong, membranous or
coriaceous or indurate, much thinner above, keeled, 2-keeled, winged on keel,
winged narrowly, 13–15 -nerved. Upper glume lanceolate, 5–7 mm long,
coriaceous, keeled, 1-keeled, 3 -nerved. Upper glume surface glabrous. Florets.
Basal sterile florets 1, male, with palea. Lemma of lower sterile floret 75 %
of length of spikelet, hyaline or membranous, 3 -nerved.

Fertile lemma 4–5 mm
long, without keel, 3 -nerved. Lemma apex lobed, awned, 1 -awned. Median
(principal) awn from a sinus, 9–15 mm long overall, with a twisted column.
Grain 1 mm long.

: Africa, Temperate Asia, Tropical Asia, and Australasia.

: Northern Territory.

Northern Territory: Darwin &

Notes. A few
collections from northern N.T. Throughout the Old World tropics. Flowers Apr.

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