One cannot imagine that this is a kinfd of lettuce. It is unique in having a tuber underground. The flowers open in nightime and normally close already in morning. In cloudy days they stay open, like this one. I was really lucky this time.
Lactuca tuberosa is a tuberous plant with a milky sap. The beautiful flowering heads open at night and close as soon as the sun comes out, in cloudy days they remain open till noontime.
