swamp spider orchid

Caladenia paludosa is a terrestrial, perennial, deciduous, herb with an underground tuber. It has a single erect, hairy leaf, 100–300 mm (4–10 in) long and 5–15 mm (0.2–0.6 in) wide. Up to three red, greenish-yellow and cream-coloured flowers 30–50 mm (1–2 in) long and 50–80 mm (2–3 in) wide are borne on a stalk 300–500 mm (10–20 in) tall. The sepals have thick, brown, club-like glandular tips 10–25 mm (0.4–1 in) long. The dorsal sepal is erect, 35–60 mm (1–2 in) long and 3–5 mm (0.1–0.2 in) wide. The lateral sepals are 35–60 mm (1–2 in) long and 4–5 mm (0.16–0.20 in) wide and curve stiffly downwards. The petals are 30–45 mm (1–2 in) long, 2–4 mm (0.08–0.2 in) wide and curve upwards. The labellum is 7–25 mm (0.3–1 in) long, 8–16 mm (0.3–0.6 in) wide and greenish-yellow with a glossy red tip which curls downwards. The sides of the labellum have linear teeth up to 5 mm (0.2 in) long and there are four widely-spaced pale or deep red calli along its mid-line. Flowering occurs from September to early December.

The swamp spider orchid is found on the coastal plain between Gingin and Gracetown in the Jarrah Forest, Mallee, Swan Coastal Plain and Warren biogeographic regions. It grows in thick scrubland which is swampy in winter.