Caladenia douglasiorum
(D.L.Jones) G.N.Backh.Flowering plant 10–25 cm tall. Leaf 6–11 cm long, 5–8 mm wide. Flower solitary; perianth segments 2.8–4.5 cm long, greenish cream to yellowish with red striae; dorsal sepal erect, lateral sepals and petals divergent, tips drooping; dorsal sepal flattened at base, 2–3 mm wide, tapered to a filiform, clubbed tail, club 6–10 mm long, with dark red to blackish, globose, sessile glands; lateral sepals flattened at base, 4–5 mm wide, tapered to filiform clubbed tails, clubs 6–10 mm long, similar to those of dorsal sepal; petals shorter than sepals, flattened at base, 2–3 mm wide, tapered to an acuminate apex, sometimes with a narrow club 2–4 mm long. Labellum curved forward with apex recurved, lamina ovate to ovate-lanceolate, unlobed or obscurely 3-lobed, 13–15 mm long and 8–9 mm wide (when flattened), cream with red veins and a deep reddish apex; marginal calli on lateral lobes, red, linear, 1–3 mm long, diminishing in size and merging towards the apex; lamina calli in 4 rows, often yellowish, moderately crowded, extending onto base of mid-lobe, foot-shaped, c. 1.5 mm long at base of lamina, decreasing in size towards apex. Flowers Sep.–Oct.
Gold. Endemic to Victoria where known only from heathy open forest on sandy loam in the Dalyenong-Emu area of the western goldfields.
Known from a single locality on private property and regarded as critically endangered.
Caladenia douglasiorum is most similar to C. australis, but the former has larger, more distinctly yellow flowers, shorter labellum calli and a narrower column.
