Thornless crown of thorns (Euphorbia geroldii) is a beautiful small  ( up to two and half feet diameter) shrub from dry and tropical forests of Madagascar. It is an outstanding, rewarding and generally undermarketed species that will thrive and bloom most of the year when kept near a sunny window or outdoors in part shade. It can be used as a landscape plant in warm areas with only light overnight winter frosts. We have grown it successfully as an ornamental in vivariums housing small species. This plant is considered critically endangered because of habitat loss.