Kupilu, Poison Nut (Strychnos nux-vomica) – Properties, Benefits, Dosage Description of Plant Kupilu (Strychnos nux-vomica) is medium sized tree with short and crooked trunk. Wood of the tree is close grained, white colored, very hard and durable. Plant bears irregular branches that are covered with smooth and ash grey colored bark; young shoots of the tree are dark green in color. Leaves are simple opposite, oval about 4 inch long and 3 inch broad, shiny and smooth from both upper