It is a genus that includes only one species, Decarya madagascariensis, also commonly called "geometry tree" or "zig-zag plant", referring to the habit of its green stem, consisting of segments that abruptly change their direction. In the intersections, pairs of opposite thorns come out, which are robust and not very long. It is a rare cactus (also due to its shape that almost resembles a small shrub), which in nature reaches even six meters in height, but its growth is also very slow and for this reason it is often found more easily in the grafted variant.