It looks like a seedling from your SAC. The young leaves on mine in the spring often have that silver veining down the center of the leaf. The coloration disappears on mine as the weather warms up. SAC is known to be a notorious seeder. To prevent it in the future, shear the plant back after the flowers fade and prior to the seeds developing and ripening.

Thanks for the info.

I'll keep an eye on it, I like the varigation and would love for it to stay, but if not.... c'est la vie!

Alexa

It's imitating your hosta!! LOL!
Linda C