Dimorphochloa rigida S.T. Blake, Pap. Dept. Bot. Univ. Queensland 1(19): 2 (1941).
Classsification.
(GPWG 2001) : Subfamily Panicoideae. Paniceae.
Type of Basionym or
Protologue Information: IT: S.T. Blake 7711, 19 Feb 1935, Australia:
Queensland: Darling Downs Dist., 335 m (holo: BRI; iso: BRI, CANB, K, L, US-2962846, US-1819218).
Recent synonyms: Cleistochloa rigida.
Key references
(books and floras): [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of
Australia, [2008] S.W.L.Jacobs, R.D.B.Walley & D.J.B.Wheeler, Grasses
of New South Wales (187).
Illustrations:
[2008] S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South
Wales, 4th edn (187).
Habit.
Perennial. Rhizomes present, short. Culms erect, 30–80 cm tall, wiry, 8–20
-noded. Mid-culm nodes pubescent. Lateral branches branched. Leaves cauline.
Leaf-sheaths smooth, hairy. Ligule a fringe of hairs, 0.4–0.8 mm long.
Leaf-blades flat or involute, 2–10 cm long, 1.5–5 mm wide. Leaf-blade surface
smooth, indumented.
Inflorescence.
Inflorescence solid, a panicle. Panicle linear, 4–9 cm long.
Spikelets.
Spikelets pedicelled. 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, dorsally
compressed, 4.3–5.6 mm long.
Glumes. Glumes
thinner than fertile lemma. Upper glume elliptic, 3.3–4.9 mm long, scarious,
without keels, 5 -nerved. Upper glume surface indumented. Florets. Basal
sterile florets 1, barren, without significant palea. Lemma of lower sterile
floret 90 % of length of spikelet, membranous, 5–7 -nerved.
Fertile lemma 4.3–5.6
mm long, without keel. Lemma surface indumented. Lemma apex mucronate. Palea
without keels. Anthers 3.
Continental
Distribution: Australasia.
Australian Distribution:
Queensland, New South Wales.
Queensland:
Burnett, Darling Downs, Leichhardt, Maranoa, Mitchell, Moreton, Warrego, Wide
Bay, Port Curtis. New South Wales: Central Coast, Central Tablelands,
Central-Western Slopes.
Notes.
In C. rigida, copiously branched axillary branches develop in the latter
part of the year and these are terminated by cleistogamous spikelets. This
development pattern is similar to that of Panicum subgenus Dichanthelium.
In C. subjuncea, the axillary branches are frequently undeveloped or
absent and the solitary cleistogamous spikelets occur in the culm axils.
In Brigalow forests,
tropical and subtropical sub-humid woodlands, temperate sub-humid woodlands,
and semi-arid shrub woodlands. Flowers Feb.-June (-Nov.).
