Epilobium obcordatum is a species of perennial plant in the evening-primrose family (Onagraceae), known by the common name rockfringe willowherb[citation needed] and rock fringe.

[2] This small perennial is clumpy to mat-forming and spreads from a woody caudex, especially in nooks between rocks.

It has stems lined with oval or rounded leaves which spread parallel to the ground or ascend somewhat.

The petals are magenta to purple, rounded and notched, often in a perfect heart shape, and are one or two centimeters long.

The glandular, club-like, ridged fruit is a capsule two to four centimeters long growing on a short stalk.