Arrowhead (wapato)
Sagittaria
Botanical family: Alismataceae
An emergent plant recognisable by its spear-head leaves, hence its name, that rise 50-90 cm out of the water, and by its white three-petalled flowers. Lewis and Clark ate it abundantly during their expedition (1804-1806) among the Chinook of the Columbia River. In China, a traditional New Year vegetable: it's thinly sliced, blanched, stir-fried. A taste between water chestnut and potato.
Full sun
Clayey mud, a ledge 10-30 cm below the water
Emergent plant, feet permanently submerged
Very hardy (-20 °C, tubers sheltered in the mud)
Overwinters in your zone
Insect-pollinated (white 3-petalled flowers, June-August)
Role in permaculture
An ancestral starchy tuber, the 'wapato' of the peoples of the Pacific Northwest and the Chinese 'cí gū', grown for millennia in Asia. Each plant produces in autumn 5 to 15 small tubers (1 to 4 cm) at the end of underground stolons, to be harvested in a controlled way by baskets, in winter, when the surface has withered. A little-invasive plant, an ideal complement to the cattail in the edible pond.
Good companions
Traditional companion planting (benefit not demonstrated)
Poor companions
Invasive species: smother the habitat
Insects attracted or useful
Seasons & availability
Increased by its rhizomes and tubers rather than from seed, arrowhead gives its starchy tubers from late summer into the heart of winter, once the foliage has died down.
Available: January, February, September, October, November, December.
Guidance for the oceanic / temperate climate; it may vary with your region, altitude, exposure and growing method.
Nutritional & medicinal properties
For educational purposes. Not a substitute for medical advice. Effects depend on the form, the dose and personal context.
Precautions & contraindications
To be eaten cooked only: raw, the tuber contains an acrid and unpleasant juice, with irritant saponins, that attenuates on cooking (peeling then boiling or frying). At the young-leaf stage, possible confusion with the water arum (Calla palustris), toxic: the arrowhead has spear-head leaves with two clear points downward, the arum rounded heart-shaped leaves; only gather with a sure determination. In wild picking, the species is becoming scarce and is protected or threatened in several French regions: check the regional red list before any gathering, and prefer growing it at home. Like any nourishing aquatic plant, it can accumulate the pollutants of the water, and rainwater is not free of PFAS: according to Cousins et al. (2022, Environmental Science & Technology), PFOA levels in rainwater exceed US drinking-water health advisories even in remote regions, and PFOS levels often exceed them. Take into account the origin and quality of the water for a regular food harvest (see the concept 'Rainwater quality').
Species & varieties
The best-known species and varieties in France.
Species
Voices of peoples
Paraphrases attributed to their documented sources. Never an invented quote.
Chinook peoples and tribes of the Columbia River · Pacific North-West coast, North America
The Chinook women harvested the wapato, Sagittaria latifolia, the American sister, by wriggling barefoot in the mud during autumn and winter, until the tubers rose to the surface. A whole female economy rested on this slow gesture in the cold water. Lewis and Clark recount the practice in their journals, without always gauging its centrality.
Daniel E. Moerman, Native American Ethnobotany, Timber Press, 2010 ; Erna Gunther, Ethnobotany of Western Washington, 1973.
Regulatory status in Europe
A species' status varies from one country to another: check before growing, selling or foraging it outside France.
FranceProtected species
Protected by regional decree in several regions (Auvergne, Limousin, Midi-Pyrénées): gathering is prohibited there. Elsewhere the species is becoming rare, prefer cultivation to wild picking.
Arrêtés régionaux de protection de la flore (Auvergne 1990, Limousin 1989, Midi-Pyrénées 2004) ; statut consolidé par l'INPN (MNHN)
Before you forage
This plant is often gathered from the wild. Only pick what is abundant, never a protected species, and never uproot a whole plant (roots) without the landowner's permission. Rules vary by country and region, check locally.
Key takeaways
- • Prefers full sun exposure.
- • Ideal soil: clayey mud, a ledge 10-30 cm below the water.
- • Classic companion: Cattail (bulrush).
- • Keep away from: Water primrose.