Brasiliopuntia brasiliensis is a tree-like, perennial cactus with a peculiar habit and mode of growth at once distinguish this species. It rises with a perfectly straight erect slender but firm and stiff round trunk to a height to 9 or more metres tall, very gradually tapering to a point furnished all the way up with short mostly horizontal or declining branches bearing bright green branches of flattened, oval, spiny segments. The whole plant resembles a straight taper pole artificially dressed up with branches. The main stem is perfectly round and sheds 2-3-year-old side branches. The pale yellow flowers open in long succession in spring-summer, only on adult plants over 60-100 cm tall, and are followed by small, yellow fruits. A number of species have been described in the past, but are now considered only to be variants of B. brasiliensis.