Species of
Oxera show a variety of growth forms, including
lianas,
shrubs and
trees. The leaves are simple, and are petiolate (on short stalks), except in
O. sessilifolia, with entire or occasionally sinuate (wavy) edges. The
inflorescences are loose
thyrses of flowers, growing from leaf axils (axillary) or directly from the stem (
cauliflory). The flowers are large, conspicuous and bisexual; the
calyx is actinomorphic (rotationally symmetrical), but the
corolla is zygomorphic, sometimes strongly so. Although some species have four
stamens in each flower, they are usually reduced in number with two stamens, usually the posterior pair, forming
staminodes instead. ==Distribution==