Photographs: the Gearagh, Co. Cork

Lesser Marshwort Helosciadium inundatum (Apium inundatum) Smaileog bháite Family: Apiaceae Flowering time: June-September. Perennial. Native. Very small umbels of 2-4 rayed white flowers in leaf axils. Submerged leaves deeply tripinnate, hair-like feathery appearance. Upper leaves with three-lobed or pinnate narrow leaflets. More/less prostrate. To 40cm Shallow water or waterside mud. Decreasing due to habitat loss. Similar: Helosciadium x moorei is the very rare, sterile hybrid with Fools Water-cress, H. nodiflorum. The submerged leaves are less finely divided and it rarely flowers

Lesser Marshwort, Helosciadium inundatum (Apium inundatum), Smaileog bháite