Acaena pinnatifida is a species of flowering plant in the family Rosaceae.

Acaena pinnatifida is known from California (in the United States), and in South America (Chile to Argentina).

[2] In North America, the species grows on roadsides, sand dunes, rocky slopes and coastal grasslands.

[4] Acaena pinnatifida was first formally named and described in 1798 by Hipólito Ruiz López and José Antonio Pavón (Spanish botanists) in the Flora Peruviana, et Chilensis journal.

[2] In English, Acaena pinnatifida is commonly known as the Argentinian biddy-biddy and as the California sheepbur.