''Iva annua'', the annual marsh elder or sumpweed, is a North American

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of ...

annual plant An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. Globally, 6% of all plant species and 15% of herbaceous plants (excluding trees and shrubs) are ...

in the family

Asteraceae Asteraceae () is a large family (biology), family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the Order (biology), order Asterales. The number of species in Asteraceae is rivaled only by the Orchi ...

that was historically cultivated by Native Americans for its edible seed.

Description

''Iva annua'' is an annual herb up to 150 cm (5 feet) tall. The plant produces many small flower heads in a narrow, elongated, spike-like array, each head with 11–17 disc florets but no ray florets. Marshelder has a unique odor when the leaves or pollen are touched, but this odor is not present in winnowed seed. Cultivated varieties of Marshelder (var. macrocarpa) bred by Native Americans possessed seeds 6-9mm in length; whereas wild-type Marshelder has seeds 3 mm in length on average (not exceeding 4.5 mm).

Distribution

It is native to northeastern Mexico (

Tamaulipas Tamaulipas, officially the Free and Sovereign State of Tamaulipas, is a state in Mexico; one of the 31 states which, along with Mexico City, comprise the 32 federal entities of Mexico. It is divided into 43 municipalities. It is located in nor ...

) and to the central and southern United States, primarily the

Great Plains The Great Plains is a broad expanse of plain, flatland in North America. The region stretches east of the Rocky Mountains, much of it covered in prairie, steppe, and grassland. They are the western part of the Interior Plains, which include th ...

and

Mississippi Valley The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Ita ...

as far north as

North Dakota North Dakota ( ) is a U.S. state in the Upper Midwest, named after the indigenous Dakota people, Dakota and Sioux peoples. It is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minneso ...

. There are some populations in the eastern US, but these appear to represent introductions.

Conservation

NatureServe NatureServe, Inc. is a non-profit organization based in Arlington County, Virginia, United States, US, that provides proprietary wildlife conservation-related data, tools, and services to private and government clients, partner organizations, and ...

evaluated ''Iva annua'' in 1998 as globally secure, G5.

Uses

''Iva annua'' was cultivated for its edible seed by Native Americans around 4,000 years ago in the central and eastern United States as part of the Eastern Agricultural Complex. It was especially important to the indigenous peoples of the

Kansas City Hopewell The Kansas City Hopewell were the farthest west regional variation of the Hopewell tradition of the Middle Woodland period (100 BCE – 700 CE). Sites were located in Kansas and Missouri around the mouth of the Kansas River where it enters the Mi ...

culture in present-day

Missouri Missouri (''see #Etymology and pronunciation, pronunciation'') is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it border ...

and

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...

. The edible parts contain 32 percent protein and 45 percent oil. However, like its relative ragweed, sumpweed possesses many objectionable qualities which include being a severe potential

allergen An allergen is an otherwise harmless substance that triggers an allergic reaction in sensitive individuals by stimulating an immune response. In technical terms, an allergen is an antigen that is capable of stimulating a type-I hypersensitivi ...

and possessing a unique odor. Probably for these reasons it was abandoned after more pleasant alternatives (such as

maize Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout grass that produces cereal grain. It was domesticated by indigenous peoples in southern Mexico about 9,000 years ago from wild teosinte. Native American ...

) were available and, by the time Europeans arrived in the Americas, had disappeared as a crop.

References

External links