Psoralea pinnata (Blue Pea) Fabaceae Bob Scudder, San Francisco Bob brought in a generous branch in bloom of this South African species covered with 0.5-inch white and violet blue pea-like flowers. It is a tall shrub, to 12 feet and is not overly frost hardy. We have a native species (P. esculenta), found from Montana to Oklahoma, with edible tuberous roots.