Sub-species
subsp. aspleniifolius     Fernleaf Ironwood, Santa Cruz Island Ironwood
This tree grows to 12 m (40m) tall and has leaves that are up to 200 mm (7ľ in) long that are palmately to pinnately compound with 3-7 linear leaflets that are up to 140 mm (5˝ in) long.

It is found in the Channel Islands and grows from an altitude of 20 m (65 ft) to 500 m (1640 ft) and in its native habitat it is rare and threatened by over grazing. It is the more commonly cultivated tree and is planted in large gardens or parks as a specimen or along borders as a tall screen.