Flowering stem 30–60 cm tall. Leaf-blade to 15 cm long and 4–10 mm diam. at base, mostly green, apex lax. Flowers 10–40, greenish with brownish markings, fragrant, in a moderately crowded spike 8–15 cm long; ovary obovoid, to 4 mm long; sepals 6–9 mm long, dorsal sepal ovate-lanceolate, acuminate, striated, lateral sepals free, divergent, lanceolate, erect, margins strongly incurved, tips bidentate; petals linear, 6–9 mm long, incurved or spreading, apex pale, acute to obtuse. Labellum on a short broad claw, white to pinkish, ovate, 6–9 mm long, concave throughout, margins crisped or undulate, compressed near bend; callus tongue-shaped, greenish, channelled, thickest at the bend, but extending well beyond, often verrucose. Column appendages pale, hatchet-shaped, to 3 mm long. Flowers Dec.–Jan.
GleP, VVP, VRiv, WaP. Extremely rare, occurring in grassland and sedgeland on heavy black loamy soil prone to inundation. Known to persist only in a few small populations in south-west Victoria.
The type population from near Portland has been eradicated through clearing for agriculture.
Prasophyllum diversiflorum is part of the P. frenchii complex. It differs from other members of this complex in its late flowering period, laterally compressed labellum and more distinctly hatchet-shaped column appendages.