Ludwigia peruviana aka Peruvian Primrose Willow

Ludwigia peruviana is a shrub in the evening primrose family, Onagraceae. Its native range runs from southern Mexico through tropical America. Kew places it in the wet tropical climate zone. It describes the plant as a subshrub or shrub. The RHS records that it is not native to Britain or Ireland. These sources give no hardiness rating for garden use.

The plant has several stems and a partly woody frame. Virginia Tech records a height of up to 12 feet (3.7 metres). Its account does not give a separate range for garden plants. The shrub makes suckers, which add stems to its form. Young twigs are green and hairy, with ridges along them. Their oval buds range from green to brown. Bark ranges from green to grey-brown and peels in long strips. This peeling bark contrasts with the hairy growth on young shoots.

The leaves grow in an alternate pattern along the stems. Each leaf has one blade rather than separate leaflets. Leaf shapes range from ovate to lanceolate: egg-shaped to narrow and pointed. Some leaves lack a stalk and sit against the stem. Others have a very short leaf stalk. Hairs cover both the upper and lower leaf surfaces. The veins stand out on the blades. Leaf edges have fine teeth or a fringe of hairs. Small stipular leaves often occur at the leaf base.

The flowers are yellow to pale yellow and draw attention. Each grows alone in a leaf axil, where leaf meets stem. Flowers reach about 0.13 feet (0.04 metres) across. Most have four rounded petals, though some have six. Virginia Tech describes the species as monoecious. Its account places the main flowering season in late summer. The fruit is a brown capsule with a box-like shape. Capsules measure about 0.04–0.08 feet (0.01–0.03 metres) long.

The evidence gives a fuller account of form than garden care. It does not set out light needs or soil preferences. Nor does it provide a mature spread or cold tolerance. Showy flowers, hairy leaves, and peeling bark are its documented visual traits. The supplied accounts do not assess food uses or toxicity. They also give no species-level account of pests or diseases.