how do you tell apart Northern and Southern Catalpa, really?
OK, I confess.
They're often derided, but I like Catalpas. Always have.
However, with the exteptions of the golden and purple leaved cultivars, I have a LOT of trouble telling apart the two native Catalpas...C. bignonioides & C. speciosa.
The only thing I can go off of is *usually* C. speciosa grows larger.
Are there any good "clues" to tell the difference?