Meet Florida native Oxalis corniculata (Common Yellow Woodsorrel). Common Yellow Woodsorrel occurs in almost every county in Florida. There are two native Oxalis in Florida. Oxalis corniculata Common Yellow Woodsorrel) and Oxalis micrantha (Tufted Yellow Woodsorrel). You may have seen the pink or purple flowering Oxalis, but these are not native. Both Florida native Oxalis species are yellow, making them easy to differentiate from the exotics. Telling these two apart can be as easy as a simple observation. Oxalis micrantha has more upright stems than Oxalis corniculata and does not root at the nodes. Oxalis micrantha has only sparse hairs on its fruits and its leaves lack stipules, the outgrowths born on either side (sometimes just one side) of the base of a leafstalk. Furthermore, according to Atlas of Florida Plants Institue for Systemic Botany, Oxalis micrantha occurs in North Florida and as mentioned above, Oxalis corniculata occurs throughout the entire state.
The heaviest bloom time is typically in the spring, followed by many seed packed pods. The seed pods will eventually burst open and disperse themselves a good distance, reseed and can be aggressive. However, this behavior is a good thing where Oxalis corniculata can make a nice ground cover with its numerous, charming and cheery yellow blooms. I encourage this spread in our landscape where it creates a nice ground cover between pavers along a walking path.