Arthraxon castratus (Griff.) Nayaran.
ex Bor. Fl.Assam 5: 376 (1940).
Classification. (GPWG 2001) : Subfamily Panicoideae. Andropogoneae.
Basionym and/or
Replacement Name: Andropogon
castratus Griff. Not. Pl. Asiat. 3: 89 (1851).
Type of Basionym or
Protologue Information: "Suddyah in campis graminosis: January 2nd,
1836", Griffith 292 (HT: K) IGS: "See Hack. Monog. 349.".
Key references
(books and floras): [1980] M.Lazarides, Tropical Grasses S.E.Asia
(21), [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia.
Derivation: L. castro,
castrate. Sessile spikelet of pair only one present.
Habit.
Perennial. Culms sprawling, 60–200 cm tall. Mid-culm nodes glabrous.
Leaf-sheaths hairy. Ligule a fringed membrane, a ciliolate membrane, 1.2 mm
long. Leaf-blades lanceolate, 3–11 cm long, 6–15 mm wide. Leaf-blade surface
glabrous or indumented.
Inflorescence. Inflorescence solid, a rame. Racemes flexuous. Rhachis
fragile at the nodes.
Spikelets.
Spikelets sessile, 1 in the cluster. Companion spikelets pedicelled, 1 in the
cluster. Companion spikelets represented by barren pedicels. 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, 6–8 mm long.
Glumes.
Glumes dissimilar, firmer than fertile lemma. Lower glume lanceolate,
chartaceous, without keels, 7–9 -nerved. Lower glume surface glabrous. Upper
glume lanceolate, chartaceous, keeled, 1-keeled. Florets. Basal sterile
florets 1, barren, without significant palea. Lemma of lower sterile floret
hyaline or membranous.
Fertile lemma 4.4–5.5
mm long, without keel, 1 -nerved. Lemma apex entire or lobed, awned, 1 -awned.
Median (principal) awn dorsal, 10–20 mm long overall, with a twisted column.
Column 6–8 mm long. Palea present. Anthers 3. Grain 2.5–3.3 mm long.
Continental
Distribution: Temperate Asia, Tropical Asia, and Australasia.
Australian
Distribution: Queensland.
Queensland:
Cook.
Notes. Only one
Australian record from sclerophyll woodland of Horn Is., Torres Strait. India,
Sri Lanka. Flowers July.
