A deciduous shrub, 2 to 3 ft high; branches very leafy, covered at first with minute down. Leaves roundish to oval or ovate, 1⁄3 to 1 in. long, pointed or blunt at the apex, more or less downy beneath, sometimes with sinuous margins, but otherwise entire. Flowers stalkless, produced in June and July in two- to five-flowered spikes in the upper leaf-axils, and the end of the shoot. Corolla pinkish white, 1⁄4 to 1⁄3 in. long, between funnel and bell-shaped, shallowly five-lobed; hairy towards the base inside; style glabrous and, like the stamens, enclosed within the corolla. Fruit white, oval or nearly globose, 1⁄4 in. wide.
Native of the southern Rocky Mountains, of little garden value. It belongs to the subgenus Anisanthus, in which the corolla is funnel-shaped or rotate, the tube twice or three times as long as the lobes.
S. microphyllus H.B.K. S. montanus H.B.K. – A native of Mexico, introduced in 1829 and figured in Bot. Mag., t. 4975, but probably not now in cultivation. It is a shrub to about 10 ft high, with acute leaves not much over 1 in. long, glaucous and downy beneath. Flowers mostly axillary, solitary or in pairs. Fruits white or white flushed with pink. It is of interest as a parent of S. × chenaultii (see under S. orbiculatus) and through it possibly of some of the Doorenbos hybrids. It is the type-species of the subgenus Anisanthus.
S. oreophilus A. Gr. – Another close ally of S. rotundifolius, native of the southern Rocky Mountains; introduced in 1898. It differs from that species in minor characters and is only of botanical interest.