I would guess a lack of cold-hardiness did in your *O. santa-rita* hybrids, given the natural range: http://efloras.org/object_page.aspx/… I've got a bright pink *O. polyacantha* v. *hystricina*, but it's never set fruit, so it may have a different chromosome number than other species I've had blooming at the same time. All others I've flowered are yellow, though I have some reds and near whites coming along. Efloras has chromosome counts for native species, which might give you an idea of what's likely to hybridize easily, though there's a lot of variation within species. http://flickr.com/photos/58877781@N00/… Sean Z SE Michigan