You’ll see it nodding its lemony-yellow flowers along sidewalks and wild trails. Most little kids will recognize the clover-like leaves and smooth green stem. This is sourgrass (Oxalis pes-capre), an invasive with a pleasantly tart and tasty flavor.
Also known as Bermuda buttercup, buttercup oxalis, and yellow oxalis, this little plant was introduced as an ornamental from South Africa and now is found throughout coastal California, as well as in Arizona and Florida. The flowers, stems and leaves are all edible and make a nice trailside snack, or addition to a salad.
Flowers Of Marin 