Geranium caespitosum (purple cluster geranium, pineywoods geranium) is a perennial herb native to the western United States and northern Mexico. Its US distribution includes Arizona, Colorado, Nevada, New Mexico, Texas, Utah, and Wyoming. It has a purple to red flower with 5 stamens, and the sepals are acuminate, tapering with a long point. It has palmately lobed leaves. The fruit is a schizocarp made up of 5 mericarps. It grows in damp soils, as in the understory of coniferous forests and in canyons.