The fruit of puncture vine or caltrop, Tribulus terrestris (Family Zygophyllaceae), is this structure with ten sharp points, capable, when mature and very hard, of puncturing a tire or a foot. There are also shorter emergences elsewhere on the fruit. At maturity, the fruit is dry and split into five segments, called nutlets. The armature on this fruit is an adaptation also for dispersal, when a segment becomes lodged in fur.