dunno if this will clarify or not from my non-scientific viewpoint, but here goes. i had i. pennata for several yrs. then, after i got too vigorous in weeding that out, i found a source of seeds for i. quamoclit, which i'd seen and wanted really bad. anyhow, it seems more seedy/weedy than pennata, and comes up all over(no hope of weeding it all out)- but always with the extremely fine ferny foliage. i have some regular ipomeas(blue heaven, saucers, granpa otts, etc.- those are multifidas) that bloom at the same time and all over each yr, but have never seen them cross with or noticed any recognisable crosses of them and quamoclit(or pennata when i grew it). the common multifida ones cross every which way but loose with each other, but at least for me they haven't boogied with quamoclit. pup- i understood your question, but don't know the answer. it makes sense that it would be part of the genetic grab bag, but i haven't seen evidence of it. maybe your yard/experience is just that. i didn't mean that species don't or can't cross earlier, just that if the seeds are pure species, they should come true. we count on seedsman to label things correctly and breed them true. there's no way to really tell, though, just by the seeds(or plants), but i hadn't seen those 2 buggers cross or spontaneously mutate. however, because the common names are so similar, they certainly could get mixed up in a seed packet. and, who's to say some birds or storms didn't help along with some seeds from neighbor's yards? anyhow, i probably was making too many assumptions & should have kept my lip buttoned. i hope i didn't hurt any feelings. and, that's a good ? about what you call a species that can't cross. anyone?

I have lots of Lobelia cardinalis, it self sows here and there in interesting places, and I usually transplant and expand or create another patch. Transplanting L. cardinalis is easy, however I would not try to divide a Cardinal flower as they make a rosette of foliage and my instinct says it should stay intact. However I've never tried it. L. cardinalis has been fairly long lived. If you deadhead and pamper a bit with water and compost, it will successfully make offsets each year. The original 2 pots I bought at the nursery in 2007 are still alive, and also 2008 winter-sown plant and their seedlings. I have been growing Cardinal Climber for 3 years and it has never reseeded, but have successfully collected seed. Last year the deer went to town on the CC and the MGs on my new trellis and so I constructed barriers, which allowed some recovery to the vines and decent showing of blooms. The hummers nectar regularly on CC, but they LOVE cardinal flower. I think it is their very favorite plant in my garden. Here's a pic from last year -

Home Harvest Seeds has them as well... direct link below. Here is a link that might be useful: Home Harvest Seeds Annuals A-C

I`ve started cyprus vine indoors for the first time. The picture on the pkg are of white starlike blooms. Your red vine is beautiful and so are cardinal birds, I`d be tempted to say, your vine is cardinal. I must look for that. I`m looking for info on Cup and Saucer vine for my zone 5b. Wish they would put zones on pkgs.