Boisduvalia macranthaBoisduvalia pallida Epilobium pallidum is a species of flowering plant in the evening primrose family known by the common name largeflower spike-primrose.

It is native to western United States, where it grows in moist areas in northern California, Oregon, and Idaho.

The inflorescence atop the stem bears several flowers and hairy, leaflike bracts.

Each flower has four bilobed petals each up to about a centimeter long and bright pink in color.

The fruit is a beaked capsule between 1 and 2 centimeters long containing a row of tiny seeds.