Claytonia perfoliata, is an annual herb that is native to western North America.
The common name miner's lettuce refers to its use
by California Gold Rush miners who ate it to get their vitamin C to
prevent scurvy. It can be eaten as a leaf vegetable.
Most commonly it is eaten raw in salads, but it is not quite
as delicate as other lettuce. Sometimes it is boiled like spinach,
which it resembles in taste.
The small pink or white flowers have five petals 2–6 mm long; they appear from February to May or June, and are grouped 5–40 together above a pair of leaves that are united together around the stem to appear as one circular leaf.
Mature plants have numerous erect to spreading stems that branch from the base.
(from Wikipedia)