Cactus - Astrophytum Myriostigma
This wonderful cactus flowers regularly. The picture tells the story!
Sow in a good cactus compost that is well draining. Keep at a temperature of 17 - 20C and keep on a windowsill. Water thoroughly when soil is dry to the touch. Keep in the seed tray for as long as possible and pot up when large enough to handle.