It is endemic to coast of southern California, including the Channel Islands.

Erysimum insulare grows on coastal bluffs and sand dunes.

[1] Erysimum insulare is a perennial herb or subshrub producing a branching, erect stem 5 to 60 centimeters tall.

The longest leaves near the base of the stem may be up to 15 centimeters long.

The top of the stem is occupied by a raceme inflorescence of many bright yellow to yellow-orange flowers.