Palmer's grapplinghook

Harpagonella is a genus of flowering plants in the borage family. They are known as the grappling-hooks, because of the appearance and function of their fruits. The strange fruits are two small nutlets enclosed in a burlike calyx, which is armed with numerous spines covered in minute, hooked barbs. These diminutive, annual plants are found in sandy, clayey, and gravelly soils, and have small white flowers. This genus is native to North America, and is found in southern California, southern Arizona, northern Sonora, and the Baja California peninsula.

The genus has been regarded as one of the most morphologically distinctive of the Amsinckiinae, largely because of their unusual fruits. The genus was formerly monotypic, but the plants native to Arizona have since been recognized as a distinct species.