It has one or two relatively large, greenish-yellow flowers whose lateral sepals have thin brown "clubs" on their ends.

Caladenia crebra is a terrestrial, perennial, deciduous, herb with an underground tuber and a single hairy leaf, 10–20 cm (4–8 in) long and 6–10 mm (0.2–0.4 in) wide.

[1][2] Caladenia crebra was first formally described by Alex George in 1971 and the description was published in Nuytsia from a specimen found south of Dongara.

[4] The Arrowsmith spider orchid is widespread and common between Dongara and Jurien Bay in the Geraldton Sandplains and Swan Coastal Plain biogeographic regions.

[1][5] Caladenia crebra is classified as "Not Threatened" by the Western Australian Government Department of Parks and Wildlife.