Nature at Hand has a FREE weed identification guide for invasive plants of the San Gabriel Mountains that can be downloaded.
http://www.natureathand.com/Main/NAHWeedGuide.htm
Free Invasive Plants Guide
Some of those weeds are quite common. Some are also cultivated and widely planted in So Cal., e.g., African Daisy, fig trees and eucalyptus.
With he exception of one of the thistle variations, I am pretty sure I've seen all of them at one time or another, especially in the foothills while working on various debris basins, typically located where homes are located along forrest boundaries.
With he exception of one of the thistle variations, I am pretty sure I've seen all of them at one time or another, especially in the foothills while working on various debris basins, typically located where homes are located along forrest boundaries.