Plinthanthesis paradoxa (R.Br.) S.T.Blake

Plants with base forming a hard woody bole. Culms 0.5–1 m high. Inflorescences 9–15 cm long. Spikelets 6–8 mm long, with 3–4 florets. Glumes shorter than or equalling florets, exceeding basal lemmas, acute; lower glume 5–7 mm long, 7-nerved, microscaberulous apically and along nerves. Lemma: body 2–3 mm long; lobes 0.8–1.2 mm long, shorter than body, partially fused to awn (or each other if awn absent), without setae; awn sometimes present, often short, 0.5–1.2 mm long, bent, shorter than lemma lobes. Palea 3.2–4 mm long. Anthers 2–3 mm long, purple. Caryopsis obovate, 1.5 mm long.

Grows in marshy habitats on sandy or peaty soils,often along the coast in coastal heath over sandstone.