Yellow woodsorrel(Oxalis stricta
) is a herbaceous annual or perennial that is native to North America. It looks very similar to shamrocks. It produces yellow flowers with five petals that bloom between May and October. The leaves are usually green, but can also be purplish or brownish red in color. O. stricta
will curl up it's leaves at night, and open them during the day. O. stricta
often grows alongside wild violets, cleavers, and wild onions.
can be toxic to horses if large amounts are consumed over a short amount of time. All parts of the plant contain oxalic acid (oxalates), which vary in toxicity depending on the stage of growth of the plant, environmental conditions, time of day, and part of the plant.