Schizachyrium pachyarthron C.A.Gardner. Fl.
Western Austral. 1: 336 (1952). Classification. (GPWG 2001) : Subfamily
Panicoideae. Andropogoneae.
Type of Basionym or
Protologue Information: HT: Holmes s.n., May 1943, Australia:
Western Australia: Northern Province: Kunmunya Mission, Camden Sound (PERTH; IT:
BRI).
Key references
(books and floras): [1952] C.A.Gardner, Flora of Western Australia 1
Gramineae (336), [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of
Australia.
Illustrations:
[1952] C.A.Gardner, Flora of Western Australia 1 Gramineae (335,
Pl. 98).
Habit. Annual.
Culms 50–100 cm tall, 0.5–2 mm diam., 5–13 -noded. Lateral branches branched.
Leaf-sheaths smooth or scaberulous. Ligule an eciliate membrane, 0.2–0.6 mm
long. Leaf-blades conduplicate, 1.5–10 cm long, 0.8–3 mm wide.
Inflorescence.
Inflorescence solid or compound, a rame, a panicle of rames. Rhachis fragile at
the nodes.
Spikelets.
Spikelets sessile, 1 in the cluster. Companion spikelets pedicelled, 1 in the
cluster. Companion spikelets rudimentary, comprising 2 unequal glumes without
lemmas, 1.5–3 mm long. Companion spikelet glumes awned. 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, 5–8 mm long.
Glumes.
Glumes dissimilar, firmer than fertile lemma. Lower glume lanceolate,
coriaceous, keeled, 2-keeled, winged on keel, winged narrowly. Lower glume
surface glabrous or indumented. Upper glume lanceolate, membranous, keeled,
1-keeled, wingless or winged on keel. Upper glume surface glabrous or
indumented. Florets. Basal sterile florets 1, barren, without
significant palea. Lemma of lower sterile floret 75–100 % of length of
spikelet, hyaline, 2 -nerved.
Fertile lemma 4–6 mm
long, without keel, 1 -nerved. Lemma apex lobed, awned, 1 -awned. Median
(principal) awn from a sinus, 19–30 mm long overall, with a twisted column.
Column 8.5–11 mm long. Palea absent. Grain 2.3–3.5 mm long.
Continental
Distribution: Australasia.
Australian
Distribution: Western Australia, Northern Territory, Queensland.
Western Australia:
Gardner. Northern Territory: Darwin & Gulf, Victoria River, Central
Australia North. Queensland: Burke, Cook, North Kennedy, Port Curtis,
Gregory North.
Notes. Fairly
widespread annual on sandy soils in tropical Australia and subtropical coastal
Qld. Flowers Mar.--Sept.
