Chrysopogon oliganthus

Chrysopogon oliganthus Veldkamp. Austrobaileya 5: 526 (1999).

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

Basionym and/or Replacement Name:  Vetiveria pauciflora S.T. Blake, Pap. Dept. Bot. Univ. Queensland 2(3): 20 (1944).

Type of Basionym or Protologue Information: HT: S.T. Blake 8639, 19 Apr 1935, Australia: Queensland: Burke Dist. (BRI; IT: US-1865534).

Recent synonyms: Vetiveria pauciflora.

Key references (books and floras): [1952] C.A.Gardner, Flora of Western Australia 1 Gramineae (324 as Vetiveria pauciflora), [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia.

Illustrations: [1952] C.A.Gardner, Flora of Western Australia 1 Gramineae (321, Pl.104 as Vetveria pauciflora).

Habit. Perennial. Rhizomes present, short. Culms erect, 60–120 cm tall, 4–6 -noded. Lateral branches simple. Ligule a fringe of hairs. Leaf-blades 25–55 cm long, 2.5–5 mm wide.

Inflorescence. Inflorescence compound, a panicle of rames. Panicle lanceolate, 11–17 cm long, 1.2–5.5 cm wide. Rhachis fragile at the nodes.

Spikelets. Spikelets sessile, 1 in the cluster. Companion spikelets pedicelled, 1 in the cluster. Companion spikelets developed, male, 4.5–7.5 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, linear or lanceolate, laterally compressed, 4.5–7 mm long.

Glumes. Glumes dissimilar, firmer than fertile lemma. Lower glume lanceolate, cartilaginous, without keels, 4–5 -nerved. Upper glume lanceolate, cartilaginous, keeled, 1-keeled. Upper glume apex muticous or mucronate. Florets. Basal sterile florets 1, barren, without significant palea. Lemma of lower sterile floret 50–70 % of length of spikelet, hyaline, 2 -nerved.

Fertile lemma 3–4 mm long, without keel, 1 -nerved. Lemma apex entire, awned, 1 -awned. Median (principal) awn apical, 1.5–15 mm long overall. Palea 0 -nerved, without keels. Anthers 3. Grain 3 mm long.

Continental Distribution: Australasia.

Australian Distribution: Western Australia, Northern Territory, Queensland.

Western Australia: Gardner, Fitzgerald, Dampier. Northern Territory: Darwin & Gulf, Victoria River, Barkly Tableland. Queensland: Burke, Cook, North Kennedy.

Notes. Creek banks and flood-flats in tropical Australia. Flowers Apr.--Jun. & Sept.--Oct.

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