Description from Flora of China
Shrubs or small trees, rarely large trees, evergreen. Leaves petiolate or rarely sessile and amplexicaul; leaf blade leathery to thinly leathery, margin serrate, serrulate, or rarely entire. Flowers axillary or subterminal, solitary or rarely to 3 in a cluster. In C. subg. Thea flowers clearly pedicellate; bracteoles differentiated from sepals, 2-10, spirally arranged, persistent or caducous; sepals 5(or 6), persistent, distinct or basally connate. In C. subg. Camellia flowers apparently sessile, actually with a short stout pedicel completely covered by bracteoles and sepals at anthesis; bracteoles and sepals not differentiated, ca. 10, caducous or persistent. Petals 5-8(-12), white, red, or yellow, basally ± connate. Stamens numerous, in 2-6 whorls; outer filament whorl basally ± connate into a tube and adnate to petals; anthers dorsifixed, 2-loculed, longitudinally and laterally cleft. Ovary superior, 3-5-loculed, placentation axile. Capsule globose or oblate, 3-5-loculed, sometimes reduced to 1- or 2-loculed by abortion, loculicidal into (1-)3-5 valves from apex; columella persistent or lacking. Seeds globose, semiglobose, or polygonal; testa hornlike; hilum umbilicate; cotyledons full and fleshy with high oil content; endosperm absent.
Camellia renshanxiangiae C. X. Ye & X. Q. Zheng (Acta Phytotax. Sin. 39: 160. 2001) is not treated here because we have been unable to see the type or other authentic material and are unable to evaluate the species. Camellia renshanxiangiae is described as having pilose anthers, which are otherwise unknown in Camellia but do occur in Adinandra.
Some of the varieties of Camellia used in this treatment may represent extremes in a range of variation that in reality is continuous and would be better treated by just describing the pattern of variation within an overall species. Additional study may show that fewer varieties are justified in being recognized than are represented in the present treatment.
The main economic value of Camellia is the production of tea made from the young leaves of C. sinensis var. sinensis and C. sinensis var. assamica. The next most economically important species is C. oleifera which has the longest history of cultivation and utilization in China for oil, used primarily in cooking, extracted from its seeds. Other species used locally for seed oil production include C. chekiangoleosa, C. drupifera, and C. reticulata.
Camellia species are of great ornamental value, especially C. japonica, C. reticulata, and C. sasanqua Thunberg, with by far the greatest number of named cultivars being those of C. japonica, although many other species have ornamental potential. Other species have been used ornamentally for hybridization, particularly with C. japonica, to incorporate desirable characteristics such as the yellow petal color of C. petelotii, the frost hardiness of C. oleifera, or the fragrance of C. grijsii and C. lutchuensis. The species C. hiemalis Nakai, C. maliflora Lindley, C. rosiflora Hooker, C. sasanqua, and C. uraku Kitamura were treated in FRPS (49(3). 1998) but occur in China only as cultivated plants and are therefore not treated here.
About 120 species: Bhutan, Cambodia, China, NE India, Indonesia, S Japan, S Korea, Laos, Malaysia, Myanmar, Nepal, Philippines, Thailand, Vietnam; 97 species (76 endemic) in China.