It’s the middle of January and much of the country is in a deep freeze, but here on the edge of the Pacific Ocean’s warming waters, certain plants have decided that Spring has sprung. This stand of sourgrass forms part of a scattered necklace ringing the North Basin and the west shore of the park.
As any plant authority will tell us, it’s not a grass at all. It’s oxalis pes-caprae, aka the common yellow woodsorrel, lemon clover, pickle plant, and various other names that it also shares with completely different species. It’s a native of South Africa, now found in many parts of the world. It prefers bad soils, of which there is no lack in Cesar Chavez Park.
The plant is not beloved of gardeners because once established, it is hard to get rid of. The reason is that it forms numerous small bulbs underground, and pulling up the plant leaves the bulbs in the soil to make new plants next season. One of the charms of Cesar Chavez Park is that here you can feast your eyes without guilt on the unbounded spread of pretty plants that you hate.
Wikipedia has this to say about its uses:
The plant is palatable and in modest quantities is reasonably harmless to humans and livestock. In South Africa it is a traditional ingredient in dishes such as waterblommetjiebredie (water flower stew).
The plant has been used in various ways as a source of oxalic acid, as food, and in folk medicine. The raw bulbs have been used to deal with tapeworm and possibly other worms. The plant has been used as a diuretic, possibly hazardously, in the light of observations in the following section. The lateral underground runners, which tend to be fleshy, have been eaten raw or boiled and served with milk. The golden petals can be used to produce a yellow dye.”