Perennial with deeply descending root c. 1-3 cm. diam. near stock. Stems simple or rarely 2-3-branched, stout, striate, margined, 3-4·5-(6) dm. tall. Basal Ivs ∞, rosulate, 5-10-15 cm. × 6-15-20 mm., coriac., us. fleshy, oblong or narrowly oblong-spathulate, 1-3-nerved, obtuse or sub-acute, narrowed to short or long petiole. Cauline Ivs 2-5-(7·5) cm. long, narrow-oblong to narrow-lanceolate. Infl. a terminal compact umbelliform or corymbose cyme 5-15 cm. diam., or occ. much larger; pedicels slender, margined. Calyx us. c. 1/2 length corolla, campanulate to tubular, cut hardly 1/2 way into deltoid-lanceolate or subulate acute to acuminate lobes; sinus broad. Corolla white, 12-20 mm. diam. or more, cut c. ⅔ way into broad-oblong rounded lobes.