Want small Cassius tree to attract butterflies

We are looking for a small cassius tree to attract butterflies in our garden.WE are on the coast in Del Mar.
Garry

Hi Garry! --

There is no better choice than Cassia (now Senna) bicapsularis, which you can see in bloom at Buena Creek Gardens in San Marcos. There are two varieties, 'California Gold' with bright golden-yellow flowers, and 'Butter Creme', with pastel-yellow flowers. Another good one is Senna splendida. All these are naturally big shrubs, but you can train them as small trees. I've seen them offered as trained "standards" in some nurseries.

Steve Brigham

Thanks Steve that's very helpful
Garry