Boykinia purpusii Brandegee, Bot. Gaz. 27: 447. 1899 (as purpusi); Sullivantia purpusii (Brandegee) Rosendahl; Therofon purpusii (Brandegee) A. Heller

Flowering stems 5-40 cm. Leaf blades 1-10 cm wide, 5-11-lobed for 1/3-1/2 length, lobes cuneate to cuneate-oblong, 1-2 times dentate. Flowers: sepals triangular, 0.8-1.7 × 0.7-1.2 mm; petals ovate to ovate-lanceolate and gradually narrowed into claw; ovary ca. 2 times as long as wide. Capsules narrow-cylindric, 4-8 × 1.5-2.7 mm, 2.5+ times longer than wide. Seeds 1.1-1.7 mm. 2n = 14.

Flowering Jun-Aug. Hanging gardens of moist canyon walls and wet cliffs (sometimes at high elevations), often near waterfalls; water in suitable habitats often highly charged with calcium carbonate; 1800-3200 m; Colo.

Variety purpusii is found in the Gunnison and White River basins.