Barbados-Nut, Physic Nut, Poison Nut, Bubble Bush, Purging Nut
Jatropha curcas is a tree that can grow up to eight meters high when growing wild. Its natural area of distribution reaches from Mexico to Argentina. As a crop plant, it is cultivated in tropical and subtropical regions around the globe (distribution map).
This plant, known as Barbados-nut, physic nut, poison nut, bubble bush and purging nut, is highly toxic in all parts and contains curcin. Probably because of this, it is not very well known as a houseplant and is very rare to find in the plant trade.
Growing Jatropha curcas from seeds
I grew the little tree shown here from seeds. In a semi-shaded location, in late winter at temperatures around 18 °C.

The seeds do not remain germinable for very long and must be sown quickly. I soaked them for about 24 hours before sowing.
The sowing depth can be one to two centimeters. At about 18 °C, it takes four to six weeks for the first seeds to germinate.

I used a mixture of peat-free herb soil and bird sand as substrate. The location for growing was semi-shaded, only in the morning hours the pot was sunned for an hour.
Out of five seeds, only two germinated and only one seedling was able to develop into a small tree.
How to care for Jatropha curcas as a pot plant
Jatropha curcas tolerates sunny to semi-shady locations. As substrate I use a mix of peat-free herbal soil, bird sand and pumice gravel. The pot ball should be allowed to dry out between waterings but not dry out.