Abelia R. Br. (1818), in the family Caprifoliaceae, contains around 30 species in eastern Asia and 1 or 2 in Mexico.
Description Upright or scrambling shrubs to 4m. The leaves are opposite, evergreen or deciduous, ovate to lanceolate, usually without teeth. The flowers are white, purplish, or crimson, often yellowish in the throat, often scented, solitary or few in the upper leaf axils. Sepals 2–5, joined at the base. Petals 5, short, spreading, forming a 2-lipped corolla, joined at the base to form a tube. Stamens 4, in 2 pairs, attached at the base of the tube. Ovary inferior, with 3 cells, but only 1 cell fertile, with 1 ovule; style 1, simple, with a capitate stigma. Pollination is by bees, moths, or hummingbirds. The fruits are leathery, with 1 seed, topped by the persistent sepals.
Key Recognition Features The large, often paired and persistent sepals are characteristic, combined with the 2-lipped flowers.
Evolution and Relationships The family Caprifoliaceae is now considered to include the traditional Dipsacaceae, which covered such genera as Dipsacus, the teasel, Valeriana, and Scabiosa. But it excludes Viburnum and Sambucus, elder, which are now placed in the Adoxaceae. Within Caprifoliaceae, Abelia is close to Dipelta and Kolkwitzia.
Ecology and Geography In scrub and on cliffs; most species are from China, with 1 species, A. triflora R. Br., in the northwestern Himalayas. Abelia floribunda Decne is from Mexico; it has tubular, crimson flowers, and it is this species that is pollinated by hummingbirds.
Comment The garden hybrid A. x grandiflora (André) Rehd. is very commonly planted in warm areas, where it will flower almost throughout the year. The genus was named after Dr Clarke Abel (1760–1826), botanist and surgeon who visited China with Lord Amhurst in 1816–17 and died at Cawnpore. His plant collections, which survived the wreck of the Alceste, were described by Robert Brown in 1818.