Last year I started some various Hibiscus and Rose of Sharon seeds and them moved them out into my yard. The Hibiscus seeds were given to me from someone on another plant site and were all had the ID on the baggie. The plant you see is what is coming up in a place where I had planted one of the Hibiscus however it's definitely not a Hibiscus I've been told. The location is in Central Texas. The leaves on the plant are heart shaped and have a waxy appearance and feel to them. If you rub your fingers across them they don't slide like on a regular leaf. I'm not sure if the 2nd to last photo shows an emerging bud or new leaves. Staked up it's about 4' high. The 3rd photo shows the stalk where it comes up out of the ground It's already been suggested that it could be possibly Basella rubra but I don't believe it is as I've looked it up and the stalks seem to all have a reddish coloration. It's also been suggested that it could be some kind of Vietnamese vegetable but if so I have no idea where it could have come from. It's growing right out of the square area where I planted a Hibiscus. The last photo is before I staked it up the other day. It's been in the ground since mid-June this year.
I looked at that Michael, the leaves don't look quite right. I'm still waiting to see if any buds are going to form.