Happy-Go-Lucky Shamrock (Oxalis)
But what is a shamrock? The original Irish shamrock, spelled seamróg, which means, "summer plant" is said by many to be none other than white clover (Trifolium repens), a common lawn weed native to Ireland. This vigorous perennial grows in clusters of three heart-shaped leaves on a thin, green stem. Occasionally, a fourth leaflet will emerge, making a "four-leaf clover," and is believed to bring good luck to anyone who finds it.