All
Adenia are
perennial plants, but there are many different forms, including herbs, vines, shrubs, and trees. Many are
succulents and some are
pachycauls. Some have fibrous root systems and some have
tubers.
Adenia have alternately arranged leaves borne on
petioles. There are two glands located near the attachment of the leaf blade to the petiole. Most species are
dioecious.
Inflorescences of a few to many flowers occur in the leaf axils. There is a
stipe below the flower. The
calyx has five lobes and the five
petals are usually smaller than the
sepals and may be whitish or greenish. The male flower has five
stamens. In the female flower these are reduced to
staminodes. There are three
styles tipped with stigmas that may be long-hairy to very woolly. The fruit is a red capsule. Each black seed has a fleshy
aril.
Adenia species can be difficult to identify and distinguish as individuals of a species can be variable. One plant can have leaves of varying shapes and sizes, and young and old specimens can have different leaf types. Some taxa are poorly represented in
herbarium collections, leaving few examples to compare with new specimens. Records of some taxa lack descriptions of both (i.e. male and female) flower types. Many species only flower for a few weeks, and during this time they may also lose their leaves. Succulent plants can be difficult to properly collect and preserve. == Cytology ==