Wild Calla is a native erect perennial that is semi-aquatic growing 5 to 10 inches high.
The leaves emerge first and are all basal, arising from the rhizome. They are green, large, somewhat waxy and heart shaped with a pointed tip and with a 2 to 6 inch stalk. Leaf veins are curved, parallel and ascending. Leaf margins are frequently incurved toward the mid-rib.
The inflorescence is a separate flowering stem rising from the rhizome. The flower stalk is usually shorter than the upright leaves. It has a knob shaped 1 to 2 inch spadix covered with tiny yellow-greenish flowers that are partly surrounded by a white open oval to elliptic spathe. Occasionally plants have been found with two or three spathes.
Flowers are mostly bisexual and have from 9 to 12 stamens, but sometimes 6, that are of two types - outer stamens with broad filaments and inner stamens with narrow filaments. Each ovary of the female part has from 6 to 9 ovules.
Fruit: The fertile flowers produce a cluster of berries, deep red that are somewhat pear shaped and contain brown cylindric seeds embedded in the mucilage of the berry.
Toxic: When fresh, the plant is very poisonous as it contains high levels of oxalic acid. There is literature noted below on the use of the plant for foodstuffs.
Habitat: Wild Calla is found in bogs and marshes as it is a plant of shallows, cold water, and wet soils. It can tolerate up to 2 inches of standing water and grows best in full sun. It grows from submerged creeping rhizomes that are horizontal near the surface of the soil. It can be propagated by seed or division of the rhizome.
Names: The species name palustris means "of the marshes". The genus Calla, an obscure name but thought to be from the Greek kallos, meaning beauty; in today's classification of species, only palustris is assigned to the Calla genus. The accepted author name for the plant classification, 'L.', refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy.
Comparisons: You may note the flower resemblance to garden callas, which are in the genus Zantedeschia, but in the wild, this species has no confusing relatives.
Above: The inflorescence of the Wild Calla rising on a long stalk among with basal leaves. Close-up of the inflorescence as berries are forming.
Below: Detail of the inflorescence as berries are forming. Also detail of the inflorescence and the mature red berries. Photo ©Robert R. Kowal, Wisconsin Flora.
Notes: Eloise Butler's records show that she obtained plants of this species from Glenwood Park [which surrounded the Garden] on May 31, 1907; from Mound, MN on Sept. 17, 1907 and on Sept. 13, 1908. On June 27, 1914 she brought in 12 plants from the Big Bog area of Lake Minnetonka. Martha Crone did not list it on her 1951 census, but then planted it in 1955. It is native to the NE section of Minnesota and also to certain parts of Central Minnesota in bog areas. In North America it is a plant of the north, found throughout Canada, but in the U.S. only the Great Lake States and New England down through New Jersey and Maryland. It is also found in northern Europe and Northern Asia.
Practical uses: The rhizome is edible after it is dried, processed and then the resulting meal is boiled. It can then be used as flour but not by itself - it should be mixed with regular wheat flour. Accounts of this go back to Linnaeus where the resulting product was called "Missen bread". Linnaeus stated that the resulting bread "proves a tough as rye bread, but is perfectly sweet and white. It is really, when new, extremely well-flavored." Fernald (Ref. #6) has a page devoted to how this was done. The dried berries are edible.
Eloise Butler wrote: "When floundering in the bogs, we come across the Wild Calla, a flower just as lovely, though smaller, as the well-known cultivated calla imported from Africa. This species has a creeping stem and heart-shaped, glossy leaves. It belongs to the Arum family, which includes, as you may remember, the skunk cabbage and Jack-in-the-Pulpit. Like them, too, the showy part of the inflorescence is a large bract or spathe en-wrapping a dense cluster of small flowers." Published June 18, 1911 Sunday Minneapolis Tribune
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"