Maize or Corn

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Maize or corn (Zea mays L.)

Maize or corn, a crop (a grass) most closely identified with modern Iowa, is an interloper, domesticated first in central Mexico about 7000 years ago. A genetically diverse plant adapted to many different climates, corn was grown in desert to high altitude regions and from coastal areas north to the Great Lakes.

Corn is easily recognized, and is reported at Iowa sites more than any other crop. The cobs, including cupules and kernels (two to a cupule), are the most commonly preserved elements. Early dates on corn at Rainbow (13PM91) in Plymouth County, Cormorant (13MA387) in Marion County, Sweeting (13WS61) in Washington County, and Hadfield’s Cave (13JN3) in Jones County—probably represent Late Woodland contexts. No conclusive evidence exists in Iowa prior to A.D. 1000. Undisputed and abundant corn occurs at Great Oasis, Mill Creek, Glenwood, and Oneota sites.

Paleobotanists can identify several varieties of corn used in the Midwest based on the size of the cob, number of rows, and the size and shape of the kernels and cupules. Varieties include sweet, flour, flint, dent, and pop corn. Cupules preserved in archaeological sites can provide an idea of the size of the cob. The wider the cupules and the more closed, the larger sized the cobs.

Corn is what is called a C4 plant. During photosynthesis, all plants take up carbon in the form of CO2. Some plants use a special enzyme to metabolize carbon into a molecule with four carbon atoms. Such plants are called C4 plants. Because they also metabolize almost all of a heavy form of carbon, (13C), C4 plants retain more 13C in their tissues. People who eat substantial quantities of these plants, or the animals that eat them, have more 13C in their bone collagen than those who do not. A study of bone chemistry from human skeletal remains can identify those populations who have added significant amounts of corn to their diet due to the high levels of 13C in their bone collagen. Dental health often declines in populations eating large quantities of corn due to its high sugar content.

Corn was, first and foremost, an important food plant, although cobs may also have been burned for fuel. Corn is high in carbohydrates with small amounts of protein and fat. Fresh ears of green corn were eaten boiled or roasted. Green and dried corn was also shelled, pounded, boiled, and made into corn cakes and bread. Varieties of dried corn were parched, roasted, and ground into meal or flour. Corn was also cooked with fat, meat, and other garden produce especially beans and squash. Boiled and parched corn was made into hominy. Dried—shelled and unshelled—corn was stored in woven bags and pits for overwinter, and kept as seed for the following season’s crop.

Corn smut was also eaten and used for medicine as were other parts of the plant including the stalk and pollen. Corn pollen had symbolic significance, and with other parts of the plant, was used in ceremony.

Many Late Prehistoric Iowa communities grew substantial amounts of corn and other garden crops on a grand scale creating acres of ridged gardens and fields of corn hills close to their settlements. At the Litka and Double Ditch Mill Creek sites in O’Brien County, remnants of such features still exist. Archaeologists uncover clues to the scale of prehistoric farming when they find specialized gardening and food processing implements and numerous subterranean cache pits used to store and protect garden surpluses. At the Wever Oneota site in Lee County, over 1500 such pits were uncovered.

Major References

Adair 1994, 2003, 2010
Adrain, 2003
Asch and Green, 1992
Benn, 1980, 1981
Cutler and Blake, 2001
Dunne 1995a; 2005
Gartner, 2003
Green, 1990
Powell, 2005
Moerman, 2002
Wilson, 1917
Zalucha, 1999

Map of Iowa with light yellow dots that indicate prehistoric sites known to have cultivated maize or corn

Iowa Sites
Site Number Major Reference Family Genus and Species Iowa Culture
13AM00 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays ? cf. O
13AM1 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13AM50 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13AM103 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays LW/O
13AM200 Finney and Hollinger, 1994 GRAMINEAE or POACEAE Zea mays O
13AM210 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays LW/O
13AM403 Powell, 2005 GRAMINEAE or POACEAE Zea mays LW/O
13AM404 Powell, 2005 GRAMINEAE or POACEAE Zea mays LW/O
13AM405 Powell, 2005 GRAMINEAE or POACEAE Zea mays LW
13BN103 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays GO
13BN110 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays GO
13BV1 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays MC
13CK15 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays MC
13CK21 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays MC
13CK62 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays GO
13CK402 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays MC
13DA110 Dunne, 1995 GRAMINEAE or POACEAE Zea mays GO
13DA264 Asch, 1996 GRAMINEAE or POACEAE Zea mays GO
13DK1 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13DM140 Hollinger, 1999 GRAMINEAE or POACEAE Zea mays O
13JN3 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays LW
13LA1 Asch and Green, 1992; Hollinger, 2005 GRAMINEAE or POACEAE Zea mays O
13LA27 Wright, 1999 GRAMINEAE or POACEAE Zea mays
possibly present
LW
13LA84 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13LE59 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13LE110 Asch and Green, 1992; Zalucha, 1999; Holinger, 2005 GRAMINEAE or POACEAE Zea mays LW/O
13LE117B Zalucha, 1999 GRAMINEAE or POACEAE Zea mays
possibly present
ELW
13LO2 Asch and Green, 1992;
Green and Tolmie, 2004
GRAMINEAE or POACEAE Zea mays O
13MA30 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13MA207 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13MA208 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13MA209 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13MA387 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays ELW/LLW
13ML00 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays cf. G
13ML9 Adair, 2010 GRAMINEAE or POACEAE Zea mays G
13ML12 Adair, 2010 GRAMINEAE or POACEAE Zea mays G
13ML34 Adair, 2010 GRAMINEAE or POACEAE Zea mays G
13ML79 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays G
13ML119 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays G
13ML121 Adair, 2010 GRAMINEAE or POACEAE Zea mays G
13ML124 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays G
13ML126 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays G
13ML128 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays G
13ML129 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays G
13ML130 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays G
13ML135 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays G
13ML136 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays G
13ML137 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays G
13ML138 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays G
13ML139 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays G
13ML175 Adair, 2010 GRAMINEAE or POACEAE Zea mays G
13ML176 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays G
13ML203 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays G
13ML236 Adair, 2010 GRAMINEAE or POACEAE Zea mays G
13ML361 Adair, 2010 GRAMINEAE or POACEAE Zea mays G
13ML429 Adair, 2010 GRAMINEAE or POACEAE Zea mays G
13ML637 Adair, 2010 GRAMINEAE or POACEAE Zea mays G
13OB2 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays MC
13OB4 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays MC
13OB7 Nepstad-Thornberry, 1998 GRAMINEAE or POACEAE Zea mays MC
13PK1 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13PK165 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays LW
13PK407 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13PM1 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays MC
13PM4 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays MC
13PM25 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays GO
13PM50 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays GO
13PM61 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays MC
13PM62 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays GO
13PM91 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays MW?/LW
13VB455 Asch and Green, 1992;
Zalucha, 1997
GRAMINEAE or POACEAE Zea mays LW
13WA2 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13WA105 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13WD6 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13WD8 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays O
13WD88 Dunne, 2005 GRAMINEAE or POACEAE Zea mays GO
13WS61 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays LW
13WS122 Asch and Green, 1992 GRAMINEAE or POACEAE Zea mays ?

 

Key
MW Middle Woodland
ELW Early Late Woodland
LW Late Woodland
LLW Late Late Woodland
GO Great Oasis
MC Mill Creek
G Glenwood
O Oneota

Photographs of corm plants, ears of corn and a jar of charred corn from the Cowan site (13WD88), Great Oasis

Crop ridges, agricultural field, Litka site (13OB31), Mill Creek

Topographic map of agricultural field, Litka site (13OB31), Mill Creek

Artist's reconstruction, bird's-eye view of early Great Oasis farming hamlet

Early variety of maize or corn

Corn-filled storage pit

Early variety of maize or corn

Woman grinding corn

Excavating a storage pit

Bison horn scoop

Early variety of maize or corn

Corn hills

Wittrock village site (13OB4), Mill Creek

Image Credit:
Wendy and Michael Scullin
UI-OSA Photo Archives
Melanie Riley and Mary Kathryn Rocheford, OSA (map)