sea pansy, fleshy, leaf-shaped colony of marine organisms belonging to the genus Renilla in the same phylum as the jellyfish. The colony consists of a stalk formed by a large organism called a primary polyp (see polyp and medusa) that is thrust into soft bottom material; the upper part of the stalk is composed of several kinds of secondary polyps. Sea pansies are handsome creatures; the reddish to purple upper stalk is studded with white polyps and is brilliantly luminescent. The colonies occur in the warmer regions of the Atlantic and Pacific coasts. Sea pansies are classified in the phylum Cnidaria, class Anthozoa, order Pennatulacea.