Mystery Plant…

I’m trying to figure out what this plant Folia is.

Mystery Plant Leaves and Reddish Branch

It’s a voluteer plant that has serrated leaves and a reddish truck and branches. Some people suggested that it is a Brazilian Pepper Tree (Schinus terebinthifolius), but the leaves don’t quite match the photos I’ve seen.

Click below to see more photos.

Unknown Volunteer
Leaves as a young plant

Repotted Mystery Plant
Whole plant

Mystery Plant Roots

This is growing in Vallejo, CA, USA (Northern San Francisco Bay Area), Zone 9a.

Anyone know what this plant is?