They are closely related, so You will have to wait until the foliage matures. Leaf sizes and features develop differently with different growing conditions, especially with the light intensity to temperature ratio. Bright sunny days with cool nights bring out the richness of the features.

Subrotunda leaves are more rounded than coccinea and you should be able to tell them apart once they have true leaves. The problem with subrotunda is that it can get quite wide as well as 6 feet or so tall when happy creating problems for White Nymph. That being said, you should get a nice display. One thing is for certain once you have grown subrotunda you will have plenty of seedlings.

Thank you both for the input. I hadn't considered that the subrotunda would also be wide - merely envisioned long tall wands of flowers. Excellent reason to expand the garden bed. - June