Derivation
Potamophila R.Br., Prodr. 211 (1810); from the Greek potamos (river) and -philus (loving), alluding to the habitat of the only species.

parviflora- from the Latin parvus (small) and flos (flower). Spikelets small or with few florets.

Published in
Prodr. 211 (1810).

Habit
Perennial. Rhizomes elongated. Culms aquatic, reed-like, 30–150 cm tall, 3–7 mm diam. Ligule an eciliate membrane, 4–15 mm long, lacerate, acute. Leaf-blades flat or involute, 20–50 cm long, 4–6 mm wide. Leaf-blade apex acuminate.

Inflorescence
Inflorescence compound, a panicle. Panicle contracted, lanceolate, 15–45 cm long. Primary panicle branches bearing spikelets almost to the base. Panicle branches capillary, flexuous, pubescent in axils.

Spikelets
Spikelets appressed, solitary. Pedicels filiform, 1.5–5 mm long, tip cupuliform. Fertile spikelets 1-flowered, comprising 1 fertile floret, without rhachilla extension, lanceolate or oblong, slightly laterally compressed, 3–5.5 mm long, falling entire.

Glumes
Glumes both absent or obscure or one, the lower absent or obscure. Upper glume 0.1 mm long.

Florets
Basal sterile florets 2 or more, similar, without significant palea. Lemma of lower sterile floret ovate, 0.5–1.5 mm long, membranous, 0-nerved, acute. Fertile florets bisexual (or some unisexual). Fertile lemma oblong, 3–5.5 mm long, chartaceous, 5-nerved. Lemma lateral nerves prominent. Lemma apex obtuse. Palea elliptic, 100% of length of lemma, chartaceous, 3-nerved, without keels. Lodicules 2, lanceolate, 1 mm long. Anthers 6, 2.5–3 mm long. Stigmas 2. Grain with adherent pericarp, obovoid.

Continental Distribution:
Australasia.

Australian Distribution:
New South Wales: North Coast.

Classification. (GPWG 2001):
Ehrhartoideae: Oryzeae

Notes
Endemic. Grows in or beside riverbeds. Flowers summer, Nov.–Jan.