some spurge plants have economic significance, such as cassava ("manihot esculenta"), castor oil plant ("ricinus communis"), barbados nut ("jatropha curcas"), and the para rubber tree ("hevea brasiliensis"). many are grown as ornamental plants, such as poinsettia ("euphorbia pulcherrima"). leafy spurge ("euphorbia esula") and chinese tallow ("triadica sebifera") are invasive weeds in north america.