Inflorescences dense to diffuse, 21-85 × 2-14 cm, internodes in floral branchlets 0.7-3 mm. Pedicels 0.9-3 mm. Flowers: hypanthium obconic or subglobose, long stipitate-glandular; petals tightly coiled, linear or narrowly lanceolate, 0.1-0.2 mm wide. 2n = 14.
Flowering Jun-Sep. Shaded rocks and ledges, granite, gneiss, or acidic humus over limestone or shallow rocky soil; 100-2000 m; Ala., Ga., Ind., Ky., Miss., Mo., N.C., Ohio, Pa., S.C., Tenn., Va., W.Va.
Variety villosa is found east of the Prairies in the southern Appalachian Mountains and Interior Plateau of Indiana, Kentucky, Ohio, and Tennessee. In the high mountains of North Carolina and Tennessee, the leaf lobes tend to be very sharp and narrowly triangular, and in the Interior Plateau the lobes tend to be rounded; considerable variation in lobe shape occurs throughout the range.
From Flora of Indiana (1940) by Charles C. Deam
Very local, in the crevices of cliffs or rarely in the talus at their bases. It is restricted to a few Ohio River Counties. Many years ago I dug some of the rhizomes from the crevices of rock and planted them in neutral garden soil at Bluffton, Wells County, and the plants are perfectly hardy and grow vigorously. On account of their large and rather compact cluster of basal leaves and large panicle of small white flowers I recommend it as a good garden plant, especially for borders.