The soft green leaves of Viola decumbens are narrow to linear with pointed tips. The leaves often curve downwards or their tips do. Leaf dimensions are 1,5 cm to 5 cm by 0,5 mm to 2 mm. They grow in whorls at spaced nodes from sometimes reddish stems as seen on the plant in picture.
The stems branch much and may be downy, unlike the leaves that are glabrous (hairless). These plants develop woody rootstocks (Manning, 2007; JSTOR; iSpot; Privett and Lutzeyer, 2010).