Family Euphorbiaceae > Subfamily Crotonoideae > Tribe Jatropheae.
Plants of the World Online (Kew) accepts 176 species.
Most are native to Central and South America.
A few species are from across northern Australia.
Most are evergreen or deciduous shrubs or subshrubs.
Others are perennial succulent herbs with thick tuberous roots.
There are a few small trees.
Stems have a milky or reddish latex.
Simple or glandular hairs may be present.
The alternately arranged leaves are often clustered at the branch ends.
They can be in a spiral or 2 ranks (distichous).
Most are on petioles that may have glands.
Stipules at the petiole base may persist or fall.
Stipules can be simple or (often) branched, soft or spiny and are usually without glands.
The simple leaf blades can be entire but most are palmately lobed.
There may be glands especially on new leaves.
Inflorescences are terminal or in the near terminal leaf axils.
They are on peduncles that are often longer than the leaves.
If there are any bracts they are small and they may have glandular hairs.
In almost all species the male and female flowers are on the same plant (monoecious).
The basic unit is a cyme with flowers, on a pedicel along a midrib with the terminal one opening first.
Inflorescences are often branched with each division having 2 equal branches.
On each branch the end flower is a female and the lateral (lower) ones are male.
Male or staminate flowers.
The 5 (4, 6) overlapping sepals often have their bases fused.
The 5 mostly free petals overlap and are often twisted.
Inside the petals there are 5 usually free nectar lobes.
Most of the 6 to 12 stamens are in the outer of the 2 whorls.
The filament bases are fused into a stamen column.
Dorsifixed anthers open inwards or outwards through long slits.
Any staminodes are thread-like and there is no ovary.
Female or pistillate flowers.
These have sepals and petals like the male flowers but they are larger.
The disc can be annular or in 5 free lobes.
The superior ovary typically has 3 locules each with 1 ovule but 1 or 2 carpels may abort.
Attached at or near the top of each locule the ovules hang down.
The 2 or 3 styles may be fused at the base.
The 2 or 3 erect or spreading stigmas may be once divided.
Most fruit are a capsule that may open elastically.
The ovoid or almost spherical fruit are shallowly divided into the 2 or 3 lobes.
Most open down the septa (septicidal) and rarely into the locules.
Occasional fruit are drupe-like and do not split open.
The shiny seeds often have a finely divided caruncle (appendage where the seed was attached to the placenta).
J.F.
