Submerged marshwort (Apium inundatum) is a perennial aquatic plant that belongs to the floral display family (Apiaceae). The species is on the Dutch Red List of rare plants and moderately decreased. The plant is native to western Europe and Morocco.
The plant is 15-60 cm high and has a floating or mud creeping stem, which roots at the nodes. The submerged leaves are dual-suspension to triple its fine slip. The leaves above the water surface and wedge-shaped feet and are pinnate, often trilobed leaves. The leaf stem is hollow.
Submerged marshwort blooms from June to August with white, 2 mm wide flowers in a kortgesteeld, sometimes tweestralig vierstralig canopy. There are five or six carpels, but omwindselbladen missing.
The 2.5 - mm long, elliptical fruit is a two-part split fruit with relatively broad, prominent ribs.
The plant is found in shallow, moderate nutrient water in ditches, ponds and dune lakes.
See also: International Flower Delivery, Florist