mysterious Big Seedling (Cypress Vine)

This BIG seedling came up in a pot on the deck after several days of (occasional) rain. I put the photos on facebook for an ID:



Stephanie Marr wrote: "Pretty sure it's cypress vine. It has a vigorous twining habit, up to 15 feet. Small star-shaped red or white flowers last one day. Reseeds like you wouldn't believe."

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Follow-up:

There were several single flowers in September and I missed most. On September 21, there were three at once, and Holly photographed them. This gives me hope that we will have seeds!