Rickenella swartzii is a tiny agaric that is pale fray to gray-brown. The cap center (navel) is almost black. The top of the stem is tinged dark violet. It grows in scattered trooping groups in lawns and other grasslands, typically with moss.

Cap convex, expanding to nearly plane, sometimes centrally depressed; margin decurved. Flesh cream, very thin. Gills pallid, deeply decurrent, fairly well-spaced, at first whitish, then cream-colored. Spores whitish colored. Stem round, equal except enlarged at the apex; surface like the cap.