Peruvian primrose

Description:

Ludwigia peruviana as is a perennial, sometimes deciduous, wetland shrub that can grow to 3 and 4 metres. It reproduces by seed and there are many small sand-like seeds in 4 to 5 rows within a capsule and can produce soil seed banks of 1 million seeds /m2. L. peruviana's stems are brownish green, heavily branched, and hairy when young. The leaves are alternate, rarely opposite, ovate, 5 to 10cm long, 1 to 3cm wide, and hairy. The solitary flowers are bright yellow and quite showy and bisexual, 2 to 4cm in diameter, but the 4 (-5) petals last for only a day. There are 4 pale green sepals that are typically 8 to 12mm long, and petals 1 to 3cm long and wide. L. peruviana's fruit is an erect capsule. The seed is light brown, subglobular, and 0.6 to 0.8mm long. The root system consists of a woody taproot with laterals close to the surface (PIER 2005; and Sydney Olympic Park Authority 2004) and sometimes with white spongy vertical pneumatophores, especially in water.

Habitat:

PIER (2005) reports that, "L. peruviana forms dense, monotypic stands on shallow, still or slowly flowing streams, marshy areas, and streambanks." The Washington State Department of Ecology (2001) adds that L. peruviana grows in dense mats along shorelines and out into the water. It favours the margins of lakes, ponds, and ditches.

Notes:

Beautiful plant associated with river stones, occur frequently in ruderal areas. The popular belief is said to represent prosperity thanks to its splendid, bright yellow flower or sin because they always look much at the end of the year.