Claytonia perfoliata is a tender rosette-forming plant that grows to a maximum of 40 centimetres (16 in) in height, but mature plants can be as short as 1 centimetre (0.39 in). The cotyledons are usually bright green (rarely purplish- or brownish-green), succulent, long and narrow. The first true leaves form a rosette at the base of the plant, and are 0.5 to 4 centimetres (0.20 to 1.57 in) long, with a typically long petiole (exceptionally up to 20 centimetres (7.9 in) long).
The small pink or white flowers have five petals 2 to 6 millimetres (0.079 to 0.236 in) long. The flowers appear from February to May or June and are grouped 5–40 together. The flowers grow above a pair of leaves that are connected together around the stem so as to appear as a single circular leaf. Mature plants form a rosette; they have numerous erect to spreading stems that branch from the base.
C. perfoliata is common in the springtime, and prefers a cool, damp environment. The plant first appears in sunlit areas after the first heavy rains of the year, though the best stands are found in shaded areas, especially in the uplands, into early summer. As the days get hotter and drier, the leaves turn a deep red color as they dry out.