Sagittaria

Scientific name

Sagittaria L.

Common names

arrow head

Family

Alismataceae

Native distribution

mostly New World, some introduced to Old World

Species commonly cultivated

Sagittaria lancifolia L. (Americas)

S. montevidensis Cham. & Schltdl. (South America)

S. platyphylla (Engelm.) J.G. Sm. (North and Central America)

S. sagittifolia L. (Eurasia, North and South America)

U.S. Federal Noxious Weed: Sagittaria sagittifolia

Identification: The often narrowly sagittate leaf blade is a distinguishing character of S. sagittifolia. Achene (fruit) characters can help in distinguishing among Sagittaria species. In particular, relative widths of the achene wings, presence or absence of a wing on achene faces, and the relative position and orientation of the achene beak. See S. sagittifolia disseminule fact sheet.

Adventive distribution

Numerous introductions of various species throughout the world. Sagittaria montevidensis and S. platyphylla are introduced in Australia while S. subulata is introduced in Indonesia and Europe.

Weed status

Sagittaria sagittifolia is an aquatic weed on the U.S. federal noxious weed list. Several species are known as weeds in rice fields, including S. subulata, S. montevidensis, and S. platyphylla.

Habit

submersed, emergent, narrow- to broad-leaved rosette plant

Brief description

Perennial or annual. Plants submerged when juvenile, emergent when mature. Stem compact, stoloniferous. Leaves submersed, floating and emergent, in a basal rosette; petiole present or absent, elongate (when present); leaf blade linear, lanceolate to deeply sagittate, venation parallel, pinnate, or palmate; margin entire. Inflorescence erect, a peduncle bearing whorled rays of flowers. Sepals 3, green; petals 3, white, pink, yellow, or white with basal purple spot. Fruit a winged and beaked achene. Dispersal by stolon and achene.

Natural habitat

all types of water bodies with conditions of high light levels

Additional comments

A New World genus spreading throughout the Old World. The taxonomy of the genus is problematic, with little consensus from recent revisions.