Thanks, but if I'd considered provenance too heavily I'd have missed out on all the tropicals and subtropicals that thrive during our warm summers (including Bouvardia ternifolia and Sesbania tripeti, both of which bloomed heavily here in 2004).

This puzzles me: "I wouldn't expect that this species will be practical for temperennial type plantings, unless brought inside for the winter." Doesn't the generally accepted definition of "temperennial" cover plants that are not winter-hardy in a given location, but can be grown either as annuals or specimens brought indoors during the winter months?