Derivation

Paspalidium Stapf in D.Prain, Fl. Trop. Afr. 9: 15, 582 (1920); from Paspalum (another grass genus) and the Greek -idium, a diminutive but here employed as a name-forming suffix.

criniforme- from the Latin crinum (hair) and forma (appearance). Leaf-blades fine.

Published in
Proc. Roy. Soc. Queensland 62: 98 (1952).

Common synonyms
Setaria criniformis (S.T. Blake) R.D.Webster
Paspalidium gracile (R.Br.) Hughes var. debile Vickery

Habit
Perennial. Rootstock evident. Cataphylls present. Young shoots extravaginal. Culms erect or geniculately ascending or decumbent, slender, 10–60 cm tall, 4–7-noded, rooting from lower nodes. Mid-culm internodes solid or spongy, smooth, glabrous. Mid-culm nodes glabrous. Lateral branches sparsely branched. Leaf-sheaths smooth, glabrous on surface or pilose, with tubercle-based hairs. Leaf-sheaths outer margin glabrous. Ligule a fringed membrane or a fringe of hairs, 0.3–0.5 mm long. Leaf-blades flat or involute, 3–12 cm long, 1–3 mm wide. Leaf-blade surface scaberulous or scabrous, glabrous or pilose, with tubercle-based hairs. Leaf-blade margins smooth. Leaf-blade apex attenuate.

Inflorescence
Inflorescence compound, a panicle of racemes. Racemes 4–6, appressed, flexuous, unilateral, 0.5–2 cm long, 0.1–0.3 mm wide, bearing few fertile spikelets, bearing 3–10 fertile spikelets on each, simple or secondarily branched. Central inflorescence axis 2.5–12 cm long, tip filiform. Rhachis angular, 0.15 mm wide, scabrous on margins, terminating in a barren bristle-like extension, extension 2 mm long. Spikelet packing abaxial, distant, regular, 2-rowed.

Spikelets
Spikelets solitary. Pedicels 0.5–1 mm long, scabrous, tip discoid. Fertile spikelets 2-flowered, comprising 1 fertile floret, lower floret sterile, upper fertile, without rhachilla extension, lanceolate or elliptic, dorsally compressed, plano-convex, acute, 2–2.3 mm long, 0.9–1 mm wide, falling entire. Rhachilla internodes elongated between glumes, elongated below basal sterile floret, and elongated between basal sterile florets.

Glumes
Glumes thinner than fertile lemma. Lower glume ovate, gibbous, 1–1.6 mm long, 50–66% of length of spikelet, membranous, 3(–5)-nerved. Lower glume surface glabrous. Lower glume apex acute, muticous or mucronate. Upper glume elliptic, 1.8–2.2 mm long, 75–85% of length of spikelet, membranous, 5–7-nerved. Upper glume apex acute.

Florets
Basal sterile floret 1, without significant palea. Lemma of lower sterile floret similar to upper glume, elliptic, 2–2.3 mm long, 100% of length of spikelet, membranous, 5-nerved, sulcate, acute. Fertile lemma elliptic, 1.9–2.3 mm long, indurate, of similar consistency on margins. Lemma surface rugulose or rugose. Lemma margins involute. Lemma apex acute, mucronate. Palea reflexed at apex, indurate, 2-keeled. Grain with adherent pericarp.

Continental Distribution:
Australasia.

Australian Distribution:
Queensland, New South Wales.

Queensland: Burke, South Kennedy, Port Curtis, Leichhardt, Burnett, Wide Bay, Darling Downs, Moreton. New South Wales: North Coast, Central Coast, South Coast, Central Tablelands, North-Western Plains.

Classification. (GPWG 2001):
Panicoideae: Paniceae

Notes
Native. In tropical and subtropical wet sclerophyll forests, dry sclerophyll forests, tropical and subtropical sub-humid woodlands, and semi-arid shrub woodlands. Flowers mostly Feb.–July.