Tradescantia pallida (Rose) D.R.Hunt

Common Name: Purple heart, Purple queen

Purple Heart, a native of Mexico, is named for the striking purple color of the plant in full sun. Pale orchid-pink 1.3-2 cm three-petaled flowers emerge from curving double bracts at the stem tips. Purple heart blooms constantly during warm weather, but the flowers are open only in the morning. The lance shaped leaves will reach 7 inches long by 1 inch wide and are covered with pale hairs. The fleshy stems are first erect, later lying on the ground as a creeping herb, around 16 inches long. They make an attractive basket subject and can be used as an annual groundcover. Purple hearts do best in full sun to light shade. If grown in lower light levels, the plant tends to lose its purple coloring. Purple heart is propagated by cutting or from seed.
Reference
1. http://www.flowersofindia.net/catalog/slides/Purple%20Heart.html