Diamond spider orchid

Description

Caladenia rhomboidiformis is a terrestrial, perennial, deciduous, herb with an underground tuber and a single erect, hairy leaf, 120–180 mm (5–7 in) long and about 2 mm (0.08 in) wide. One or two green, yellow and red flowers 40–70 mm (2–3 in) long, 40–60 mm (1.6–2.4 in) wide are borne on a stalk 200–450 mm (8–20 in) tall. The sepals have yellowish to brown, club-like glandular tips 2–10 mm (0.08–0.4 in) long. The dorsal sepal is erect, 30–40 mm (1–2 in) long and 2–4 mm (0.08–0.2 in) wide. The lateral sepals are 25–40 mm (1–2 in) long, 4–7 mm (0.2–0.3 in) wide, turn stiffly downwards and roughly parallel to each other. The petals are 20–30 mm (0.8–1 in) long, 3–4 mm (0.1–0.2 in) wide, spread widely and are also turned stiffly downwards. The labellum is 14–16 mm (0.55–0.63 in) long, 10–11 mm (0.39–0.43 in) wide, broadly diamond-shaped and white to yellow with a deep red tip. The sides of the labellum have greenish teeth up to 2 mm (0.08 in) long and the tip is curled under. There are four rows of deep red calli along the mid-line of the labellum. Flowering occurs from September to October