Ludwigia pilosa,[1] the hairy primrose-willow, is a species of plant in the family Onagraceae.

[4] The seed box in cubed shaped with a thick exterior and estimates 3-4 mm in length.

Waterfowl feed on the seeds of the hairy primrose-willow and the immersed portion creates habitat for many invertebrates.

[4] Ludwigia pilosa prefers wet ground and can be found along road side ditches, ponds, and shallow swampy areas.

[4] Distribution spreads from eastern TX to the southern half of MS, AL, GA, NC, SC, the northern portion of FL, and two counties in southeastern VA.[6][2]