Peruvian primrose
Ludwigia peruviana
Hirsute shrub usually 0.5–3 m high, sometimes with inflated pneumatophores arising from submerged or buried roots.
Leaves alternate, ovate to lanceolate or elliptic, 4–12 cm long, 3–15 mm wide, base narrowed, ± sessile.
Flowers solitary in upper leaf axils; bracteoles ± lanceolate, on ovary base or upper pedicel. Sepals 4 or 5, lanceolate, irregularly toothed. Petals 10–25 mm long, yellow. Stamens 8 or 10.
Fruit ± obovoid, 10–20 mm long, 6–10 mm diam., 4-angled, readily dehiscent; seeds in each loculus in several rows, free.