Oxalis pes-caprae

ALL OVER my yard I have them. Where they don't shade what I planted,I leave them. Not hard to remove the tops even if the bulbs can live on and one. Not so bad an invasive.

There are pastures around here that have been taken over by this, and they are held in check by the walls. Looks great, but cows don't like it.

Your photo is nice!..It could pass for a Plumeria bloom.

It took a Portuguese friend several guesses to figure out what it is.

Often edging the bases of north-facing walls in the older neighborhoods here. Often a similar pink or white species also shows up. Both bloom in late January or early February, here.

There is a pink type flowering in a field up the street from me. But it is better behaved than this yellow one, which is very aggressive.