Sagittaria lancifolia aka Lance Leaf Arrowhead

Sagittaria lancifolia belongs to the water-plantain family. It grows in water and lives for more than one year. Its names include duck potato and bulltongue arrowhead. Its native range spans the southeastern United States, Mexico, and Central America. It grows in marshes, swamps, and wet ground by streams. It also grows in ponds, lakes, and wet roadside ditches. In gardens, it suits pond edges and other wet sites.

Plants grow in upright clumps from rhizomes, or underground stems. Garden plants reach 1–6 feet [0.3–1.83 metres] tall. Clumps spread 1–3 feet [0.3–0.91 metres] across. The smooth, dark green leaves die back each year. Their blades range from narrow to oval or arrow-shaped. Florida guidance notes lance-shaped blades, shaped like spear tips. These reach up to 2 feet [0.61 metres] long. Long leaf stalks hold the blades above the water. Large organs that store starch grow along the underground stems.

Flower stalks rise above the leaves and bear several whorls. These are rings of flowers around the stalk. Each flower has three white petals and three green sepals. The petals may show pink tints around their yellow centers. Male and female parts may grow in separate flowers. North Carolina guidance gives June to October as the bloom season. Florida guidance says most blooms come in spring. Small achenes form round heads once the blooms fade. These are dry fruits with one seed each. Water birds eat the seeds, so plantings help feed wildlife.

Give this plant full sun for the best show of flowers. It also grows in shade for part of the day. It needs soaked soil or standing water, not dry ground. It grows in sand, loam, and soil rich in organic matter. In water gardens, plant no deeper than 1 foot [0.30 metres]. North Carolina guidance lists USDA zones 6–11. Florida guidance lists zones 4–11. Reports differ on how well it copes with salt. This makes fresh water the safer choice for gardens. To grow more plants, divide clumps or plant their underground storage organs. Seeds may take up to two years to sprout.

This plant suits water gardens and projects to restore wetlands. North Carolina guidance reports no major pest or disease problems. It still says to watch for aphids and spider mites. You can eat the underground tubers after boiling or baking. Indigenous peoples also roasted them, then took off their skins. Records note the use of roots and leaves as medicine. These uses are not proven treatments. Florida guidance warns against eating plants picked in the wild. Plants that look like this one may be deadly. You must be sure which plant you have.