This plant quickly popped up in my backyard. I'm pretty sure it wasn't there last summer. Any ideas on what it is? Thanks!
Here's a close-up.
Looks like a Catalpa sapling.
Huh. I'm going to be pesky & say that I don't think it is either a Catalpa or a Cercis, but that I don't know what it actually is.
If not catalpa, then Paulownia that does not have teeth yet.
I'd put in another vote for Redbud, Cercis canadensis.
What makes me think that it isn't Cercis is the lack of a zig zag pattern to the twigs, though I've grown to respect weedwoman's ID talents throughout the years on this forum.
Carrie, look at the top image again. See the one branch in the lower part of the frame....the one coming towards the viewer? There's your zig zag alternate leaf arrangement.
It looks like redbud, to me.
Agree with redbud; probably grew quickly because it appears to be sprouting back (i.e., a bigger plant that was cut down/damaged). Those sprouts always grow quickly.