Iseilema macratherum

Iseilema macratherum Domin. Biblioth.
85: 283 (1915).

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

Type of Basionym or
Protologue Information
: Australia,
Chillagoe: Domin .

Key references
(books and floras):
[1952] C.A.Gardner, Flora of Western
1 Gramineae (351), [1981] M.Lazarides in
J.Jessop (ed)., Flora of Central Australia (492), [2002] D.Sharp &
B.K.Simon, AusGrass, Grasses of Australia.

[1952] C.A.Gardner, Flora of Western
1 Gramineae (349, Pl. 102).

Habit. Annual.
Culms erect or geniculately ascending, 25–70 cm tall. Ligule a fringed
membrane, a ciliolate membrane, 1 mm long. Leaf-blades flat or conduplicate,
10–25 cm long, 2–6 mm wide.

Inflorescence compound, composed of rames.

Spikelets sessile, 1 in the cluster. Companion spikelets pedicelled, 2 in the
cluster. Basal sterile spikelets well-developed, 4 in number. Companion
spikelets developed, male, 3–5 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, lanceolate, dorsally compressed, 6–7 mm long.

Glumes. Glumes
dissimilar, firmer than fertile lemma. Lower glume lanceolate, coriaceous,
without keels, 6–9 -nerved. Upper glume lanceolate, coriaceous, 3 -nerved. Florets.
Basal sterile florets 1, barren, without significant palea. Lemma of lower
sterile floret hyaline, 0 -nerved.

Fertile lemma 5 mm
long, 1 -nerved. Lemma apex entire, awned, 1 -awned. Median (principal) awn
20–30 mm long overall, with a twisted column. Column 8–15 mm long. Palea
absent. Grain 2.5 mm long.

: Australasia.

: Western Australia, Northern Territory, Queensland.

Western Australia: Dampier. Fortescue, Carnarvon. Northern Territory: Darwin
& Gulf, Victoria River, Central Australia
North. Queensland:
Burke, Cook, Gregory North, Leichhardt, Mitchell, North Kennedy, Warrego, South

Notes. Grows in
cracking clay mainly in the Gulf country of N.T. and Qld and isolated
occurrences elsewhere in W.A., N.T. and Qld. Flowers Feb.--Aug.

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