Northern water plantain (Alisma triviale) is a native perennial. The designation Alisma plantago-aquatica is often misapplied to this member of the Water Plantain Family (Alismataceae). A plantago-aquatica is a plantain of Eurasia that has been introduced to parts of North America.

Northern water plantain, also often called large-flowered water plantain, is a semi-aquatic to aquatic plant that grows along the edges of streams, rivers, marshes, ponds and seasonally flooded zones. It is found in all of North America except Texas and the Southeastern States.

The plant arises from a cluster of fibrous roots and rhizomes. Northern water plantain leaves grow in basal clumps. Long-petioled (stalked) and lanceolate, the leaves are thick and fleshy with prominent veins and are hairless and smooth-margined.

A leafless scape (flower stalk) rises from amid the basal leaves. The inflorescence at the top of the scape is heavily branched. Northern plantain flowers have three green sepals that are shorter than the three white to pink to purplish petals. There is a patch of yellow at the base of each petal. Six stamens and many pistils complete the flower.

Northern water plantain fruits are a ring of seeds that turn from green to brown as they ripen. Each seed is a flat-sided, grooved achene.

Muskrats and other aquatic wildlife eat northern water plantain roots. Herbalists use this plant to treat many disorders. The leaves have antibacterial properties.

The genus name, Alisma, is derived from the Celtic word (altis) meaning water. The species designation means common or ordinary.

These northern water plantain plants were growing at Ash Creek Wildlife Area (Modoc County CA) between the North and South Elkins Barns or near the south end of the dike between Elkins Ponds # 4 and #5.