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.
A small genus of deciduous or evergreen shrubs with slender branches, opposite leaves, and terminal or axillary clusters of handsome flowers. Calyx-lobes foliaceous or linear. Corolla funnel-shaped. Stamens 4, equal or didynamous. Ovary 3celled, many-ovuled. Fruit a coriaceous 1-seeded berry. Natives of Asia and Mexico, and rather tender. Named after Dr. Abel, who visited China with Lord Amherst.
1. A. triflora. - A small branching shrub with nearly sessile lanceolate entire ciliate small leaves and small pale yellow flowers tinged with pink and arranged in threes at the extremities of the branches. The calyx-lobes are long and linear, clothed with long hairs, and persistent after the corollas have fallen. North India.
2. A. floribunda. - A handsome Mexican species. Leaves glabrous, ovate, obtuse, crenate. Flowers rosy-purple, about 2 inches long, in axillary clusters. This requires protection in ordinary winters.
3. A. rupestris. - A deciduous branching hairy shrub. Leaves small, ovate, remotely serrate. Flowers small, pink, in twos, on short peduncles at the ends of the branches. The calyx-lobes are foliaceous and of a reddish tinge. A native of China.
4. A. uniflora. - This is by far the handsomest species, having much larger pink and white flowers. The calyx-lobes are foliaceous, and reduced to the number of two. Also from North China.