角胡麻科是生长在美洲的植物特有科，1981年的克朗奎斯特分类法将其列入胡麻科，两科的植物形态相近，都具有毛，所以叶子和茎都有一种喇手的感觉，果实都类似角状，但1998年根据基因亲缘关系分类的APG 分类法发现两科的基因关系并不近，因此单独列出一个科。长角胡麻属由于其蒴果的角如同动物爪，因此在美洲也被称为“魔鬼之爪”。.

Martyniaceae is a family of flowering plants in the Lamiales order that are restricted to the New World. The family was included in Pedaliaceae in the Cronquist system (under order Scrophulariales) but is recognized as a separate family by the Angiosperm Phylogeny Group on the basis of phylogenetic studies that show that the two families are not closely related. Both families are characterized by having mucilaginous hairs — which give the stems and leaves a slimy or clammy feel — and fruits with hooks or horns. Some members of the genus Proboscidea are known as "unicorn plant" or "devil's claw" because of their horned seed capsules.