Description from Flora of China
Trees, shrubs, climbers, stranglers, or sometimes woody epiphytes, evergreen or deciduous, with latex; monoecious species with male, gall (sterile female), and female flowers in each fig or dioecious with either male and gall flowers or only female flowers in each fig. Stipules often connate, lateral to amplexicaul and enclosing terminal leaf bud, caducous or ± persistent, scar ringlike. Leaves usually alternate, rarely opposite or ± verticillate; leaf blade simple to lobed, rarely palmate, glabrous or hairy, abaxially usually with waxy spots (“wax glands”) at base of leaf blade or in axil of secondary veins, with or without papillalike cystoliths, margin entire or toothed; veins pinnate to ± palmate. Inflorescences axillary or on specialized cauliflorous branches, a fig (syconium) with many minute flowers inserted on inner wall of hollow receptacle communicating with outside through an apical pore or apical pore closed by scale-like bracts, sessile or pedunculate; involucral bract usually 3 at base of fig; lateral bracts sometimes present on side of fig, scale-like, caducous or persistent. Male flowers: calyx lobes 2-6; stamens 1-3 (rarely more), straight in bud; pistillode present or absent. Gall flowers: similar to female flowers but never producing seeds and usually occupied by a fig wasp. Female flowers: calyx lobes 0-6; ovary free, straight or oblique; styles 1 or 2 and unequal, apical or lateral. Fruit a seedlike achene, usually enclosed within syncarp formed from an enlarged hollow fleshy receptacle. Seeds pendulous; endosperm usually scanty; cotyledons equal or unequal, sometimes folded.
The species of Ficus are immediately recognizable by the very distinctive inflorescence, the “fig.” Many are grown as ornamentals in tropical and subtropical regions and as house plants elsewhere, and a few, most notably F. carica, are valued as fruit trees. Fig wasps, Hymenoptera of the family Agaonidae, are very specialized symbiotic pollinators of Ficus with life cycles closely tied to the flowering and fruiting cycles of the figs. The wasp taxonomy closely parallels that of Ficus with genera of the wasps mostly being restricted to particular subgenera, sections, or subsections of Ficus. The wasp larvae feed on short-styled female flowers or, in the male figs of the dioecious species, on specialized gall (sterile female) flowers. Figs are present at some stage of development throughout the year within nearly all populations of Ficus, thus ensuring the survival of the fig wasps, which are short-lived after leaving the figs.
The genus shows considerable diversity in floral morphology and has been divided into a number of distinct genera, but the overall inflorescence morphology is so consistent and distinctive that these generic segregates never came into general use. Corner, in a series of papers (Gardens’ Bulletin, Singapore 1960–1965) divided the Asian and African members of the genus into four subgenera and a complex hierarchy of lower groups, based primarily on floral characters. Berg (Blumea 48: 167–178. 2003) modified the subgeneric classification of Corner, giving more emphasis to vegetative characters, and his scheme has been adopted for this account.
The following names of Chinese Ficus belong to taxa in other families: F. corymbifera H. Léveillé is Solanum erianthum D. Don (Solanaceae); F. hirtiformis H. Léveillé & Vaniot is Actinidia eriantha Bentham (Actinidiaceae); F. marchandii H. Léveillé is Capparis acutifolia subsp. viminea Jacobs (Capparaceae); F. ouangliensis H. Léveillé & Vaniot is Aglaia tetrapetala (Pierre) Pelegrin (Meliaceae); F. rufipes H. Léveillé & Vaniot, p.p. (Esquirol 75 and 76) is Psychotria prainii H. Léveillé (Rubiaceae); F. salix H. Léveillé & Vaniot is Salix babylonica Linnaeus (Salicaceae); F. vaniotii H. Léveillé is Aglaia tetrapetala (Pierre) Pellegrin (Meliaceae).
About 1000 species: mainly in tropics and subtropics, particularly diverse in SE Asia; 99 species (16 endemic, two introduced) in China.