During my trip to Cali, I had the privilege of visiting the greenhouse Robin Parer grows her pelargoniums in. The production greenhouse is located in an even more dicey neighborhood than Annie's Annuals, but not far from it. Robin is the proprieter of Geraniaceae, a nursery that specializes in Geranium, Pelargonium, and Erodiums. She does not sell the P. x hortorum hybrids, rather her focus is on the angel pelargoniums, scented leaf sorts, and true species. She also has a number of very unique species hybrids, including some that I created during my Ph.D. research at Cornell (Soweto Sunrise, Karoo Pride, etc) and others that originated in England (including the fascinating hybrid between tomentosum and 'Splendide'), and a series of very interesting hybrids, new to me, by J. Kapac, a hybridizer in southern California whom I do not personally know. The first pic (going clockwise) shows one of the Kapac hybrids. It shows influence from a section Pelargonium species and maybe P. trifidum. Next is the species P. acetosum, and a very fine clone thereof, with large flowers of a good color. This is a summer growing species in habitat, and it remains green throughout the year. The large white flower emerging from the soil belongs to P. carneum, a rather large flowered member of the tuberous rooted Hoarea section of Pelargonium. Section Hoarea species are great collector plants, being small and very diverse in foliage and flower. They are all winter growing, needing a dry dormancy during the summer. A cool greenhouse is best, but with good culture many can be grown indoors under lights (as I do) or perhaps in a cool and sunny house location. Finally there is the fascinating hybrid called P x caffrum, which involves the tuberous rooted section Polyactium species P. caffrum and presumably one of the scented leaf section Pelargonium hybrids, or perhaps a P. domesticum hybrid. This cross, I believe, was made in England. It gets its fimbriated petals and divided leaves from P. caffrum, and the flower color from the section Pelargonium parent.
There remains incredible potential to create many new classes of pelargonium hybrids as some of these illustrate. It seems that the larger commercial concerns are only interested in recreating the same old stuff they already sell, eg "new" zonal and ivy pelargoniums that look just like what they were selling before. One needs to look to interested individuals and smaller specialist nurseries like Geraniaceae in order to find these unusual varieties and to see really creative directions in hybridizing within the huge and diverse Pelargonium genus.
Years ago I used to visit Carol Roller when she lived in Vista, CA, where she had an amazing collection of pelargonium species and hybrids. I still remember an ivy pelargonium which crawled several meters up onto a loquat tree she had, cascading back down with loads of lavendar flowers. In that gentle climate, species like P. gibbosum grew into thick mounds of stems, foliage, and fragrant weird yellowish flowers several feet across, rather than the "chicken bone" appearance it has when confined to a small pot. Plants frequently seeded, and Carol had some nice hybrids emerge from such seeds, one I remember in particular was called Roller's Sigma, which had a lovely pink flower and attractive foliage. I also had the pleasure of visiting Michael Vassar when he lived in Van Nuys, he probably did more than anyone to introduce and distribute interesting species pelargoniums in the USA. He also had a wonderful collection of South African oxalis species. Unfortunately Michael has since passed on, way too early for such a kind, generous, and knowledgable individual. Many of his species and hybrids are being propagated by Geraniaceae, and one hopes that they thus will continue to be available to pelargonium collectors for many more years to come.