are shamrocks perennials
Oxalis makes a perennial ground cover in shady areas. Oxalis (Oxalis spp.), also called sorrel or shamrock, has a negative image if all you know of them are weedy, invasive cosmopolitan species. However, most of the about 800 species of oxalis are native plants in tropical South America and Africa or in temperate areas of the Old and New World. Many are used for landscaping or as houseplants. Oxalis are perennial plants but can give the appearance of annuals by going dormant in winter or during droughts.