Island Ironwood (Lyonothamnus floribundus) is a native tree that grows in Southern and Central California, primarily in the Channel Islands region. It tends to grow in rocky slopes, at elevations from 100-1600 feet. 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. The two subspecies have leaves of different leaf shapes. Ssp. asplenifolius (Santa Cruz Island Ironwood) has incised, fern-like leaves and is the more commonly available in horticultural form. Ssp. floribundus (Catalina Island Ironwood) has smooth, undivided leaves and is seldom seen in gardens. The inflorescence of both is a cluster of woolly white flowers with many short, whiskery stamens. The fruit is a pair of hard follicles.