// SPECIES PROFILE · EMERGENT AQUATIC · NATIVE · EDIBLE TUBERS

Broadleaf Arrowhead

Sagittaria latifolia

Instantly recognizable by its large sagittate (arrowhead-shaped) leaves with flared basal lobes, Sagittaria latifolia is the premier emergent aquatic plant of shallow ponds, sloughs, and bayous across NE Oklahoma. From July through September it sends up whorled racemes of three-petaled white flowers with yellow centers, each bloom pristine and symmetrical against the lush green foliage. In fall it produces starchy tubers known as "duck potatoes" at the ends of underground runners — a staple food for waterfowl, muskrats, and Indigenous peoples across North America for millennia. The tubers are higher in protein than true potatoes and have a nutty, chestnut-like flavor when boiled or roasted.

// QUICK FACTS

Family: Alismataceae (water-plantain family)
Group: Emergent aquatic perennial
Native range: Widespread across North America including all of Oklahoma
USDA hardiness: Zones 3–10 (Tulsa = 7a/7b)
Mature size: 1–4 ft tall, spreading by runners
Sun: Full sun to part shade (best tuber production in full sun)
Soil/water: 0–12 in water depth in rich muddy soil; pH 5.5–7.5
Water: Shallow still or slow-moving water required
Bloom time: July–September (white, 3 petals, yellow centers, in whorled racemes)
Fruit/tubers: Starchy "duck potato" tubers at ends of runners in fall
Wildlife value: Premier waterfowl food · mammals · aquatic cover · pollinators
Lifespan: Perennial; tubers overwinter and resprout
Ecological role: Emergent aquatic · waterfowl forage · fish/amphibian cover

Broadleaf Arrowhead (Sagittaria latifolia) — distinctive arrowhead-shaped leaves and three-petaled white flowers with yellow centers — *Sagittaria latifolia* — the unmistakable arrowhead-shaped leaf and white three-petaled flower. Photo via Wikipedia / Wikimedia Commons.

Identification

[ field key — arrowhead leaves · white flowers · tubers · aquatics ]

Emergent habit

Emergent aquatic perennial rising 1–4 ft above the water surface from a rhizomatous root system in the mud below. Leaves emerge on long, spongy petioles that are triangular in cross-section, allowing them to stand upright in moving water. The plant spreads aggressively by underground runners (stolons) that terminate in the starchy overwintering tubers ("duck potatoes"). A single plant can produce dozens of tubers in a growing season, forming dense colonies.

Leaves — the namesake

The leaves are the unmistakable field mark: large, sagittate (arrowhead-shaped), 4–12 in long and nearly as wide, with prominent basal lobes that flare outward and downward from the petiole attachment. The overall shape strongly resembles a broad arrowhead or barbed spear point — the Latin sagittaria means "of arrows." The upper surface is glossy medium green; the underside is paler with prominent veins. Submerged leaves, if present, are narrow and ribbon-like.

Flowers & tubers

White three-petaled flowers with bright yellow centers (stamens), 1–1.5 in across, borne in whorled racemes on a leafless stalk rising above the foliage, July–September. Flowers are unisexual but on the same plant (monoecious): male flowers are larger, with numerous yellow stamens, and occupy the upper whorls; female flowers are below with a central cluster of green carpels. The tubers are the most ecologically and culturally significant feature: round to oblong, 1–2 in in diameter, with a thin brown skin and white starchy flesh, produced at the tips of runners in late summer and fall.

Confusables

Arrow arum (Peltandra virginica) has prominently veined, not arrowhead-shaped leaves and a greenish spathe-and-spadix inflorescence (arum family), not three-petaled flowers. Pickerelweed (Pontederia cordata) has heart-shaped (cordate) leaves, not arrowhead-shaped, and purple-blue flower spikes. Water plantain (Alisma subcordatum) has oval, ribbed leaves and tiny white flowers in a diffuse panicle. Narrowleaf arrowhead (S. graminea) has much narrower, lanceolate leaves without pronounced basal lobes. S. latifolia is the only common broad-leaved, white-flowered emergent with true arrowhead-shaped foliage.

Habitat & Range in NE Oklahoma

Sagittaria latifolia is widespread across North America and is native to all of Oklahoma. In NE Oklahoma it occurs in shallow still or slow-moving water (0–12 in deep) in ponds, sloughs, oxbows, bayous, marshes, and backwater areas of streams. It is common in the Arkansas River bottomlands, where abandoned river channels, beaver ponds, and floodplain depressions create the shallow-water habitat it requires.

In the Tulsa region it can be found in farm ponds, in the wetland pockets of the Arkansas River floodplain, in the quieter backwaters of the Verdigris and Neosho rivers, and in constructed stormwater ponds and detention basins that have developed naturalized edges. It prefers rich muddy substrates with a high organic content and full sun exposure for best tuber production.

In garden settings, arrowhead is an excellent choice for water gardens, pond edges, and constructed wetlands. It establishes quickly, blooms profusely, and provides immediate wildlife value — but it spreads aggressively by runners and seed and should be contained in water garden pots to prevent it from taking over small ponds.

Ecology & Wildlife Value

[ duck potato · waterfowl · mammals · aquatic cover ]

Duck potato — premier waterfowl food

The starchy tubers are one of the most important natural waterfowl foods in North America. Mallards, wood ducks, blue-winged teal, green-winged teal, northern pintails, and gadwalls all consume the tubers heavily during fall migration and winter. The common name "duck potato" is well-earned: in managed wetlands, arrowhead tuber production is often a primary management objective for waterfowl habitat. Tubers are also eaten by trumpeter swans and Canada geese.

Mammal use

Muskrats are the primary mammalian consumer of arrowhead tubers and are important dispersal agents — they cache tubers in their lodges, and uneaten tubers sprout in new locations. Beavers also eat the tubers and foliage. Raccoons dig for tubers along pond edges when water levels drop. White-tailed deer wade into shallow water to browse the emergent foliage in late summer.

Aquatic cover & pollinators

The dense stands of emergent foliage provide critical cover for fish fry, tadpoles, and aquatic insects in the shallow-water zone. Largemouth bass, bluegill, and other sunfish use arrowhead beds as nursery habitat. The white flowers are pollinated by bees, syrphid flies, and small butterflies, and the blooming period (July–September) provides nectar and pollen during the mid-to-late summer when many other wetland plants have finished flowering.

Pests & diseases

Essentially pest-free. Occasional aquatic snails may feed on the foliage, causing cosmetic holes, but this is rarely significant. No serious diseases are recorded for this species in natural or cultivated settings. Arrowhead is one of the most robust and trouble-free aquatic plants in the native flora.

Harvesting duck potatoes by "treading." Indigenous peoples across North America harvested the tubers by wading into shallow water in fall and loosening the tubers with their toes — a technique known as "treading." The dislodged tubers float to the surface, where they are collected in baskets. This method is gentle on the plants and leaves the parent rhizome intact to produce the following year. The tubers were boiled or roasted like potatoes, dried for winter storage, or ground into flour.

Horticulture & Care

[ siting · planting · containment · harvest ]

When to plant

Plant tubers or container-grown plants in spring (March–May) after the last frost, when water temperatures are warming. Tubers can be planted directly into the mud in shallow water; container-grown plants can go in any time during the growing season.

Planting & siting

Water depth: 0–12 in of shallow still or slow-moving water. Best tuber production occurs in 6–12 in.
Sun: full sun for best tuber production; tolerates part shade with reduced vigor and fewer flowers.
Substrate: rich muddy soil with high organic content. Heavy clay pond bottoms are tolerated but sand or gravel with little organic matter will produce weak plants.
Containment: plant in 3–5 gal water garden pots with heavy clay loam soil, topped with a layer of gravel to prevent soil from clouding the water. Submerge the pot so the soil surface is 0–12 in below the water surface.
Spacing: 2–3 ft apart for a naturalized colony. In small ponds, a single contained pot is sufficient.

Maintenance

Cut back foliage after frost (November–December). Dead foliage can be left in place as winter cover for aquatic life or removed for a tidier appearance.
Divide and repot every 2–3 years to prevent overcrowding in containers. Discard excess tubers or plant them in new locations.
Control spread: in uncontained pond plantings, arrowhead spreads aggressively by runners and seed. In small ponds, containment in pots is strongly recommended. Remove unwanted seedlings by hand pulling in spring.
No fertilizer needed. The plant draws nutrients from the water and sediment.

Harvesting duck potatoes

Tubers mature in October–November. To harvest: locate the tubers at the ends of runners by feeling in the mud around established plants. Gently loosen with a trowel or by "treading" with bare feet. Tubers float when dislodged — collect them with a net or basket. Leave some tubers in place for the following year's growth and for wildlife. Tubers can be stored in damp sand or mud in a cool place through winter, or cleaned and cooked immediately. To prepare: scrub clean, peel (the skin is slightly bitter), and boil, roast, or fry. Flavor is nutty and chestnut-like, higher in protein than potatoes, and mildly sweet.

Cultural & Material Uses

Few native plants rival broadleaf arrowhead for its significance as a food plant. The tubers were a staple carbohydrate source for Indigenous peoples across the continent and remain an important foraged food in many regions today.

Indigenous staple food: known as wapato or katniss among various Indigenous nations, the tubers were harvested in fall by women wading into shallow water and "treading" to loosen the tubers. They were a primary winter food source across the Mississippi watershed, the Great Lakes, the Southeast, and the Eastern Woodlands. Lewis and Clark recorded arrowhead tubers as a vital food source for the peoples of the Columbia River region.
Nutritional profile: arrowhead tubers are higher in protein than potatoes and contain significant amounts of calcium, phosphorus, and iron. They are a gluten-free starch that can be dried and ground into flour for porridge, bread, or thickening.
Modern foraging: duck potatoes are still harvested by foragers, wild-food enthusiasts, and Indigenous communities. They are most commonly boiled and served with butter and salt, roasted alongside root vegetables, or sliced thin and fried as chips.
Wetland restoration: widely planted in constructed wetlands, mitigation sites, and restored wetland habitats for its rapid establishment, erosion control, and exceptional wildlife value.
Water garden ornamental: the arrowhead-shaped foliage and pristine white flowers make it a handsome addition to ornamental water gardens and pond plantings, where it adds a tropical appearance to temperate water features.
Bioremediation: arrowhead has shown promise in constructed wetlands for nutrient uptake and heavy metal sequestration in agricultural and urban runoff treatment systems.

Sources & Further Reading

USDA NRCS PLANTS Database — Sagittaria latifolia: plants.usda.gov/plant-profile/SALA2
Lady Bird Johnson Wildflower Center — Sagittaria latifolia: wildflower.org — SALA2
Missouri Botanical Garden Plant Finder — Sagittaria latifolia.
Moerman, D.E. (1998), Native American Ethnobotany, Timber Press — extensive records for Sagittaria latifolia.
Kuhnlein, H.V. & Turner, N.J. (1991), Traditional Plant Foods of Canadian Indigenous Peoples, Gordon and Breach — wapato harvest and preparation.
Thayer, S. (2006), The Forager's Harvest, Forager's Harvest Press — practical guidance for harvesting and preparing duck potatoes.
Tiner, R.W. (2009), Field Guide to Tidal Wetland Plants of the Northeastern United States and Neighboring Canada, UMass Press.
Wikipedia — Sagittaria latifolia: en.wikipedia.org/wiki/Sagittaria_latifolia (CC BY-SA 4.0).

Companion Planting

[ guild · polyculture · cross-layer pairings ]

In wetland and pond plantings, broadleaf arrowhead pairs naturally with: pickerelweed (Pontederia cordata), cardinal flower (Lobelia cardinalis), copper iris (Iris fulva), buttonbush (Cephalanthus occidentalis), common rush (Juncus effusus), and bald cypress (Taxodium distichum).

Site broadleaf arrowhead in shallow standing water (0–12 in) as a mid-height emergent in the pond-edge community, contained in pots to manage its spread, with taller emergents and shrubs behind and lower-growing marginals in front.