Sagittaria species may be planted from bare root stock, by transplanting the tubers, and by seeding directly into wetland soil. Live plant transplants or transplanting tubers are preferred revegetation methods where there is moving water. It takes two years for seed to germinate; planting bare root stock or tubers gives faster revegetation results.
Live Plant Collections: No more than 1/4 of the plants in an area should be collected. If no more than 0.09 m² (1 ft²)are removed from a 0.4 m2 (4 ft2) area, the plants will grow back into thehole in one good growing season. A depth of 15 cm (6 in) is sufficiently deep for digging plugs. This will leave enough plants and rhizomes to grow back during the growing season.
Wild plants should be collected after the leaves begin to emerge in the spring until the first frost. The plants can be pulled up easily from wet soil. When collecting wild plants, rinse roots gently. Leaves and stems can be clipped from 15 to 25 cm (6 to 10 inches); this allows the plant to allocate more energy into root production. The roots should always remain moist or in water until planted. Plants should be transported and stored in a cool location prior to planting. Water depth should be 0 to 6" and the soils should be wet.
Sagittaria grows prolifically around ponds or wetlands in shallow water. Plug spacing of 25-30 cm will fill in within one growing season. Soil should be kept saturated, with approximately 1/2" of water over the surface of the soil after planting. If water is low in nutrients (oligotrophic), fertilization will speed biomass production and revegetation. Many surface waters are already rich in nutrients (eutrophic), and fertilization is not necessary.
Indian potatoes transplant success may be greater with the tubers than with bare root stock. The little underground potatoes can be separated from the parent plants with a rake, hoe, or shovel. In unconsolidated soils, the tubers can be pulled up by hand by searching around the roots of the plant.
After collecting, the Sagittaria potatoes should be kept moist and cool, and stored in peat moss. Potatoes are then planted in shallow water, in the same conditions as described above for the whole plants. Potatoes should be collected and planted when plants are dormant, in the fall, winter and early spring.
Seed Germination: Seeds of Sagittaria species take two years to germinate, because they have a double dormancy requiring cold then warm then cold temperatures. Temperature has a multiple role in the regulation of timing of germination. Dormant seeds become non-dormant only at specific temperatures, non-dormant seeds have specific temperature requirements for germination, and non-dormant seeds of some species are induced into dormancy by certain temperatures. Once Sagittaria seeds germinate, they have fairly high viability. Procedures for growing Sagittaria seeds in the greenhouse have not been developed at this time.
Sagittaria seeds can be planted directly in wetlands or ponds. Prepare the area by creating a washboard in shallow water, at mudflat consistency. Seeds should then be scattered on the surface of the soil, as the seeds need sunlight to germinate well. Light and temperature in natural conditions will promote seed germination, and in two years Sagittaria plants will emerge.
Ethnobotanic: Sagittaria is an aquatic plant with tuberous roots that can be eaten like potatoes. Lewis and Clark found it at the mouth of the Willamette and considered it equal to the potato, and valuable for trade. Indian women collected it in shallow water from a canoe, or waded into ponds or marshes in the late summer and loosened the roots with their toes. The roots would rise to the top of the water where they were gathered and tossed into floating baskets. Today, the tubers are harvested with a hoe, pitchfork, or rake. Tubers are baked in fire embers, boiled, or roasted in the ashes. Tubers are skinned and eaten whole or mashed.
After roasting, some tubers were dried and stored for winter use. The Chippewa gathered the "Indian potatoes" in the fall, strung them, and hung them overhead in the wigwam to dry. Later they were boiled for use.
The tubers of Sagittaria species were eaten by many different indigenous groups in Canada, as well as many groups of Washington and Oregon (Kuhnlein and Turner 1991). The tubers were also widely traded from harvesting centers to neighboring areas. The tubers were also a major item of commerce on the Lower Columbia in Chinook Territory. Katzie families owned large patches of the plant and clearing the patches claimed ownership. Family groups would camp beside their claimed harvesting sites for a month or more.
A species of Sagittaria grows in China, and is sold in the markets of China and Japan as food, the corms being full of starch. Sagittaria latifolia is extensively cultivated in the San Francisco Bay area in California to supply the Chinese markets, and the tubers are commonly to be found on sale. The Chinese, on coming to California, used it for food and may have cultivated it somewhat. In so doing, they are believed to have extended its range into the southern part of the state (Mason 1957).
Medicinally, the Maidu of California used an infusion of arrowhead roots to clean and treat wounds. The Navajo use these plants for headaches. The Ojibwa and the Chippewa used Sagittaria species as a remedy for indigestion. The Cherokee used an infusion of leaves to bathe feverish babies, with one sip given orally. The Iroquois used it for rheumatism, a dermatological aid, and a laxative. The Iroquois used it as a ceremonial blessing when they began planting corn.
Wildlife: Tubers are planted as an wildlife food. Ducks eat the small, flat seeds of arrowheads, but the tubers are the most valuable to wildlife. Muskrat and porcupine are known to eat the tubers. Swans, geese, wood ducks, blue-winged teal, lesser and greater scaup, ruddy duck, ring necked duck, pintail, mallard, mottled duck, gadwall, canvasback, black duck and king rail are known to eat arrowhead seeds and tubers. For wildlife use, the tubers of Sagittaria latifolia are often too large and too deeply buried to be useful to ducks (Martin 1951).
Muskrats have evolved with wetland ecosystems and form a valuable component of healthy functioning wetland communities. Muskrats use emergent wetland vegetation such as Sagittaria species for food. Muskrat grazed areas increase wetland diversity by opening up the dense stands of Typha and Schoenoplectus (Scirpus) species, and providing opportunities for aquatic vegetation such as Sagittaria to become established in the open water. Muskrat huts provide a substrate for shrubs and other plant species. Indian people often sought caches of Sagittaria tubers stored by muskrat and beaver.
This perennial plant is emergent-aquatic and 1-3' tall, consisting of a rosette of basal leaves and one or more flowering stalks. Mature leaves are 4-14" long and 3-10" across; they are sagittate or hastate in shape and smooth along their margins. The leaves have conspicuous primary veins and smaller lateral veins; their venation is palmate-parallel overall. There is considerable variability in the width of the leaves and the length of their basal lobes across different populations. However, the basal lobes are at least as long as the main bodies (or terminal lobes) of the leaves. The upper leaf surface is pale green, medium green, or yellowish green, while the lower leaf surface is pale green or yellowish green. Both sides of the leaves are glabrous. The ascending petioles of the leaves are 6-18" long and rather stout; they broaden toward the base and become sheath-like. Each petiole is flat on one side, otherwise it is rounded (convex). The flowering stalks (including both peduncles & floral rachises) are about as tall as the leaves or slightly taller and ascending to erect; they are angular or terete. These stalks are either branched or unbranched; sometimes 1-2 lateral branches are produced below the rachis of the terminal stalk. Each branch of the inflorescence terminates in a raceme of whorled flowers; there are 2-3 flowers per whorl. The terminal raceme typically has 3-9 whorls of flowers, while the lateral racemes (if present) have 2-5 whorls of flowers. The whorls of flowers are spaced about 1-2" apart along each raceme. Most plants are monoecious; the male (staminate) flowers are located above the female (pistillate) flowers in each raceme. Occasionally, dioecious plants occur, and sometimes perfect flowers are produced. Underneath each whorl of flowers, there are 2-3 floral bracts that join together at the base. These floral bracts are up to ½" long, linear-lanceolate to lanceolate in shape, green, and glabrous. Each flower is about 1" across, consisting of 3 white rounded petals and 3 green ovate sepals. The male flowers have numerous stamens that are yellow, while the female flowers have clustered carpels that are green and form a small bur-like mass. The filaments of the stamens are hairless. The spreading to ascending pedicels of the flowers are up to 1" long; they are green and glabrous. The blooming period occurs from mid-summer to early fall, lasting about 1-3 months for a colony of plants. Afterwards, the female flowers are replaced by bur-like fruits that are up to ¾" across at maturity, changing in color from green to dark brown as they mature. These fruits are are globoid to subgloboid (globoid, but slightly flattened) in shape, consisting of a dense cluster of achenes. Because of the lateral beaks of the achenes, these bur-like fruits appear more streaked than prickly. The sepals of these fruits are widely spreading to recurved; they slowly wither away. Individual achenes are 2.0-3.0 mm. long, 1.5-2.0 across, and flattened-obovoid or flattened-obdeltoid in shape; some of their margins are membranous and winged. Each achene has a more or less straight beak about 1.0-1.5 mm. in length that projects laterally from its upper side. The root system consists of a tuft of coarse fibrous roots and long spreading stolons, from which starchy tubers are occasionally produced. This plant reproduces by reseeding itself or by forming clonal plants from the tuberous stolons. Colonies of plants sometimes develop at favorable sites.
Flower-Visiting Insects of Common Arrowhead in Illinois:
Sagittaria latifolia (Common Arrowhead) (On pistillate flowers, all insects suck nectar; on staminate flowers, bees suck nectar or collect pollen, while other insects suck nectar primarily; observations are from Robertson)
Sagittaria latifolia is a variably sized (2 to 20 meters in length) perennial growing in colonies that can cover large amounts of ground. The roots are white and thin, producing white tubers covered with a purplish skin a good distance (0.3 to 1 m long, 0.15 to 0.6 meter deep) from the mother plant. It is green and white. The plant produces rosette of leaves and an inflorescence on a long rigid scape. The leaves are extremely variable, from very thin at 1 to 2 cm to wedge shaped like those of Sagittaria cuneata. Spongy and solid, the leaves have parallelvenation meeting in the middle and the extremities. The inflorescence is a raceme composed of large flowers whorled by threes. Usually divided into female flowers on the lower part and male on the upper, although dioecious individuals are also found. Three round, white petals and three very short curved, dark green sepals. Male flowers are easily distinguished from female due to the dissimilarity between the 25 to 50 yellow stamens of the male and the sphere of green carpels of the female ones.
Extremely frequent as an emergent plant, broadleaf arrowhead forms dense colonies on very wet soils that become more open as the species mixes with other species of deeper water levels. These colonies forms long bands following the curves of rivers, ponds and lakes, well marked by the dark green color of the leaves. The plant has strong roots and can survive through wide variations of the water level, slow currents and waves. It displays an affinity for high levels of phosphates and hard waters.
Easily cultivated in 0.15 m to 0.45 m of water with no or little current. Plant tubers well spaced (no more than 12 plants per square meter) at the end of May at a depth of 5 to 7 cm. Fertilize with decomposed manure. Multiply through seeding or division in July. The tubers of Sagittaria latifolia and Sagittaria cuneata have long been an important food source to indigenous peoples of the Americas. The tubers can be detached from the ground in various ways: with the feet, a pitchfork, or a stick, and usually then float to the surface. Ripe tubers can be collected in the fall and are often found floating freely.
^Zepeda Gómez, Carmen, Lot, Antonio. Distribución y uso tradicional de Sagittaria macrophylla Zucc. y S. latifolia Willd. en el Estado de MéxicoCiencia Ergo Sum [online] 2005, 12 (noviembre-febrero) : [Date of reference: 18 / abril / 2014] Available in:<http://redalyc.org/articulo.oa?id=10412308> ISSN 1405-0269
^"58518-1". IPNI. 2004-07-14. Retrieved 2007-07-21. Alismataceae Sagittaria latifolia Willd. Sp. Pl. iv. 409.
^"Sagittaria latifolia - Willd. Duck Potato". Edible and medicinal plant database. Plants For A Future. June 2004. Retrieved 2007-07-20. Excellent when roasted, the texture is somewhat like potatoes with a taste like sweet chestnuts
General: Arrowhead Family (Alismataceae). Both Sagittaria latifolia and Sagittaria cuneata are aquatic plants growing in swampy ground or standing water in ponds, lakes, stream edges, and ditches (Hickman 1993). Both species have white or bluish tubers, which are edible. The leaves are sagittate, with leaf blades are either erect or floating on the surface of the water. S. cuneata leaf blades are smaller, from 5-15 cm, and the lower lobes of emergent leaf blades are less than the terminal lobe. In S. latifolia, leaf blades are from 6-30 cm, and the lower lobes of the emergent leaf blade are approximately equal to the terminal lobe. The inflorescence is simple or branching, often with the lower flowers pistillate and the upper ones staminate. The flowers are white, with three white petals and 3 sepals. Stamens are numerous and bright yellow. The pistils are numerous, spirally arranged on the receptacle. The fruit is an achene and is greenish colored. A diagnostic feature distinguishing the two species is the beak on the fruit of S. cuneata is ascending to erect and <0.5 mm; the beak on the fruit of S. latifolia is spreading and 1-2 mm.
Sagittaria latifolia has been divided into numerous species and varieties. It was divided into two varieties, based upon the presence of pubescence over the entire vegetative plant (C. Bogin 1955; K. Rataj 1972). We have examined numerous specimens and found that many from the southeastern United States are pubescent; we believe that this character alone is insufficient for recognition of the varieties.
"Fluctuations in water levels are a common feature of wetlands (Chapter 2). Consequently, wetland plants can encounter a variety of water depths seasonally and interannually. Even submersed plants may have to endure periods without standing water and most have a terrestrial form. Not surprisingly, wetland plants show a great deal of phenotypic plasticity (Fig. 4.9), and this allows them to adjust their growth as water levels change. One type of phenotypic plasticity that is widespread among macrophytes is heterophylly (Wells and Pigliucci 2000; Minorsky 2003; Dorken and Barrett 2004). Heterophylly is the ability to produce different leaf types (Figs 4.6 and 4.9). Two kinds of leaves are commonly produced by herbaceous wetland species, submerged and aerial. Submerged leaves are thin, lack or have a greatly reduced cuticle, and lack functional stomata. Aerial leaves are thicker, have a cuticle, and have stomata (Fig. 4.6). Changes in leaf shape, size, and thickness and petiole or leaf/shoot length are common in facultatively heterophyllous species. The porosity of their roots can also change significantly as soils become anoxic after flooding in flood-responders (Fig. 4.7). These morphological responses primarily serve as a way to improve oxygen uptake by leaves, the volume of internal gas storage, and the efficiency of internal gas redistribution by diffusion." (van der Valk 2006:67) Learn more about this functional adaptation.
van der Valk, A. 2006. The Biology of Freshwater Wetlands. Oxford: Oxford University Press. 173 p.