Santa Lucía, Commelina erecta
Fairly common weed, especially on land that has been tilled. There is also a white variety. According to Paraguayan lore, most "yuyos" from Quechua "yuyu" -weed- have medicinal properties. The roots or rhizomes of Santa Lucía are fairly popular.
''Commelina erecta'', commonly known as the white mouth dayflower or slender dayflower, is a perennial herb native throughout the Americas, Africa and western Asia. It is considered to be the most variable species of ''Commelina'' in North America. Fernald recognized three varieties, but Robert B. Faden has questioned their significance.