Lyonothamnus is endemic to the Channel Islands of California, where it grows in the chaparral and oak woodlands of the rocky coastal canyons.
This is a tree growing up to 15 metres (49 ft) tall with peeling reddish gray or brown bark.
The evergreen leaves are shiny, dark green with lighter undersides, and borne on short petioles.
Limited cross pollination may be a reason for low seed production/viability observed in natural populations on the island.
Discoveries of fossils have suggested that the genus once comprised several species, all but one now extinct, which grew on the mainland in the southwestern United States.