Native iris: Canyon Snow
I have had very poor results with planting native iris in my garden -- until I found Canyon Snow.
This iris was introduced by the Santa Barbara Botanic Garden.
The flowers are large and a pure white with a golden throat.
The plants increase in size each year and bloom for a long period (late April to early June for me).
I have actually had the best results growing it in a container on my patio (from which this photo was taken).
I have had good luck dividing the plant -- in the fall.