Shoulder Shrug Muscles. The shoulder shrug is a simple exercise to perform, and as the name suggests, it does work your shoulder muscles -- namely, the trapezius, or upper shoulder. Additionally, the shoulder shrug works muscles of your back -- the levator scapulae and erector spinae.
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.
Purple Shamrock grows in a clump habit of striking purple foliage. Its triangular-shaped leaves fold along the vein and look like butterflies fluttering above slender stems. Many varieties are available, including 'Triangularis' pictured here. Other common names for this plant are False Shamrock and Shamrock Plant. You can expect an abundance of soft-pink flowers to appear in spring and summer. Dainty, five-petaled blooms rise like trumpets above the mounds of purple, clover-like leaves. Don't let its fragile appearance deceive you.