Therofon heucheriforme Rydberg, Bull. Torrey Bot. Club 24: 247. 1897 (as heucheraeforme); Boykinia heucheriformis (Rydberg) Rosendahl; B. jamesii (Torrey) Engler var. heucheriformis (Rydberg) Engler; Saxifraga heucheriformis (Rydberg) M. E. Jones; Telesonix jamesii (Torrey) Rafinesque var. heucheriformis (Rydberg) Bacigalupi

Flowering stems 30-230 cm. Leaves: stipules of cauline leaves 1-2 mm (often fimbriate, sometimes foliaceous); petiole (5-)10-50(-100) mm; blade 9-50 × 13-70 mm, succulent. Pedicels densely stipitate-glandular. Flowers: hypanthium free from ovary (1.5-)2-3.5 mm, campanulate to turbinate; sepals erect, lanceolate to ovate-lanceolate, 3-6 mm, apex usually acute; petals violet-purple, ovate or spatulate, 3-6(-6.8) × 1-3.5(-5) mm, lengths ca. 1.3 times sepals, base tapered to claw; stamens (1.9-)2.5-3.3(-3.8) mm; anthers obtuse; styles connate ca. 1/2 their lengths. Capsules ovoid. Seeds 50-100. 2n = 14.

Flowering summer. Crevices of calcareous rock faces; (1500-)2500-3500 m; Alta.; Idaho, Mont., Nev., Utah, Wyo.

Plants of Telesonix heucheriformis from central and western Wyoming have petals approaching in size those of T. jamesii. Because of this, there is an argument for treating the two taxa as varieties of a single species; however, they are readily distinguishable throughout almost all of the range, have different edaphic preferences, slight differences in pollen morphology, and different flavonoid chemistries (R. J. Gornall and B. A. Bohm 1980). A report from South Dakota (P. A. Rydberg 1905c) is considered erroneous, given its age and the absence of any voucher specimens.