Family: Onagraceae
Common name: Water primrose, Hyssop-leaved water primrose, Seedbox, Linear leaf water primrose, Narrow-leaved Malayan willow-herb
Water primrose is an annual, herbaceous, semi-aquatic plant that grows along the edges of ponds and waterbodies, water-logged areas, and marshes. They are native to tropical Asian countries, but they now grow as invasive weeds in most tropical countries affecting agricultural crops.
Plant Characteristics
Water primrose plants can grow to a height of 30-100 cm tall with an erect, well-branched stem that is woody towards the base. The root system is shallow and fibrous helping the plant’s stability in wet, marshy areas.
Leaves are simple, lance-shaped, bright green in color, about 4-10 cm long, with smooth edges and a glossy surface. Leaves resemble those of hyssop plant, giving this plant its name Hyssop-leaved water primrose.
When growing in water-logged conditions, the hollow stems can help the leaves float on the surface of the water.
Water primrose plants produce small, bright yellow flowers that grow from the axils, the angle between the leaf and the stem. Each flower has 4 or 5 distinct petals and is about 1 cm in diameter.
Flowers bloom during spring and summer adding a burst of color to the landscape, attracting pollinators to it.
Water primrose plants also develop long, slender fruit capsules that are cylindrical in shape and slightly ribbed. Capsules are 2-2.5 cm long and contains numerous tiny seeds.
When they mature, these seed capsules open up to release the seeds into the water or soil depending on where they grow.
In water, the seeds are carried some distance before they touch soil and start germinating. In soil, the plant self-seeds and produces small plantlets all around the parent plant.
Growing tips
Water primrose plants are an excellent choice for water bodies, ponds, and marshy areas; thriving in water-logged conditions. They prefer rich, organic soil, but they can survive in poor soil conditions.
These plants need good sunlight, warm weather, and adequate moisture. They are considered invasive weeds, covering large areas of land very quickly, affecting agricultural crops and native species.
Since Water primrose plants grow and spread very quickly, they can choke other plants growing under it.
They are relatively easy to remove by hand-plucking, and this has to be done before the plants flowers and produces seeds.
Uses of Water Primrose
Despite its invasive nature, Water primrose plants have some medicinal uses in the treatment of cuts, wounds, pimples, boils, skin diseases, dysentery, and stomach ailments.
In its natural habitat, these plants helps in stabilizing the wetlands and mashes, prevent soil erosion, and providing shelter for small aquatic animals.
Propagation
Propagation is through seeds and stem cuttings, both very quick and effective since the stem can root easily in water.
Photographed at: Koonammavu, Kerala
