Description from Flora of China
Vines evergreen, woody, less often erect shrubs or trees, dioecious or sometimes monoecious; stems with swollen nodes. Leaves opposite, petiolate, without stipules, simple, pinnately veined, margin entire. Flowers unisexual, borne in whorled, spikelike cones (here termed "spikes"), arranged in lax, dichasial cymes. Cymes terminal or lateral, sometimes arranged in dense, cauliflorous clusters on old stems. Spikes with many cupular to almost flat, annular, involucral collars, each formed by the fusion of a whorl of bracts. Male spikes with collars closely arranged and ± hiding axis (less often somewhat laxly arranged), each collar with 20-80 flowers, often also with a whorl of sterile female flowers, apical whorl with sterile female flowers only; male flowers with a cupular, succulent false perianth, usually ± obconical; stamens 2, filaments fused, exserted from false perianth; anthers opening by a common, apical slit, pollen rounded, with minute projections. Female spikes solitary or several in a panicle, often cauliflorous; involucral collars widely separated, each with 4-12 flowers; female flowers with a false perianth tightly enclosing ovule; ovule with 2 integuments, innermost integument elongated into a micropylar tube exserted from false perianth; outer integument with a fleshy, outer layer connate with false perianth and developing into a false seed coat, inner layer bony. Seeds drupelike, enclosed in a red, orange, or yellow, fleshy (rarely corky) false seed coat; female gametophyte tissue copious, succulent. Cotyledons 2. Germination epigeal.
One genus and about 40 species: mostly tropical and subtropical Asia, fewer species in W Africa and NW South America; nine species (six endemic) in China.
Following common convention, the strictly flowering plant terms inflorescence, flower, fruit, stamen, filament, and anther are used here to avoid unwieldy descriptions.
Cheng Ching-yung. 1978. Gnetaceae. In: Cheng Wan-chün & Fu Li-kuo, eds., Fl. Reipubl. Popularis Sin. 7: 490-504.
(Authors: Fu Liguo (傅立国 Fu Li-kuo) , Yu Yongfu (于永福) ; Michael G. Gilbert)