Climbing, polygamo-dioecious shrubs; bark usually shreddy; tendrils
leaf-opposed, usually bifurcate. Leaves simple, often lobed, petiolate.
Inflorescences leaf-opposed, paniculate; peduncles sometimes cirrhiferous.
Flowers both bisexual and unisexual. Calyx saucer-shaped, subtruncate or
5-dentate. Petals 5, connate at apex, separating at base and falling off as
a calyptra. Stamens 5, straight in male and bisexual flowers; staminodes reflexed
in female flowers. Disc usually ring-shaped. Ovary pitcher-shaped; style conical,
short; stigma small; gynoecium rudimentary in male flowers. Berries globular,
succulent, purple to black, whitish to bronze or greenish, 2-4 -seeded. Seeds pyriform, shiny; adaxial surface 2-furrowed; abaxial surface 1-furrowed with
a prominent rounded or elliptic chalazal knot; endosperm T-shaped in cross
section.
In temperate and tropical regions of the Northern Hemisphere, mainly
centred in China and eastern N. America; ca 60 species, 3 in India.
KEY TO THE SPECIES
1a. Leaves nearly glabrous; inflorescences 3-7 cm long
2a. Lower surface of leaves with lax, greyish to greyish brown
tomentum; seeds with charaza depressed or indistinctly raised
at the bottom of depression on the abaxial side