This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Calyx-limb obsolete. Corolla funnel- or bell-shaped, 4-lobed. Stamens 4. There are about fifty species, a few of which are in cultivation. The name is from the Latin asper, rough. Many of the species are clothed with hispid hairs.
1. A. odorata. - This is the prettiest of the native species of this family, growing about a foot high, with from six to nine lanceolate cuspidate ciliate leaves in each whorl, and terminal cymes of white flowers. The whole plant exhales a pleasant odour when dry.
2. A. azurea, var. setosa. - This is a very handsome and very hardy annual, growing about a foot or more high. Leaves lanceolate, bristly, about eight in a whorl. Flowers sky-blue, in terminal heads. Bracts of the involucre shorter than the flowers. A native of the Caucasus.