Passage II

SOCIAL SCIENCE: This passage is adapted from "The Sacred Turnip: Dietary Clues Gleaned from Tuber Traditions, "an article by Ron Cowen that appeared in Science News (©1991 by Science Services, lnc.). The Blackfoot, or Sihasapa, are one of the seven groups making up the Lakota Indian tribe of the northern Great Plains.

Historians say the week-long sun dance adopted by the Blackfoot confederacy of Montana and Alberta, Canada, appears unique in that it gives special recognition to a stringy, bulbous tuber called the prairie turnip.

A Canadian ethnobotanist is now scrutinizing the sun dance ceremony and other Blackfoot traditions in search of clues to the prairie turnip's role in daily tribal life. So far, she says, the findings suggest that this lowly legume earned its sacred status by serving as a nutritional staple.

A key part of the Blackfoot sun dance began with the transfer of a sacred bundle to a holy woman who had pledged allegiance to the sun, says Sandra Peacock of the Fort Calgary (Alberta) Historic Park. The bundle held special garments and accessories, including a wooden stick and a headdress of buffalo hide adorned with feathers and pendants of weasel skins. According to tribespeople interviewed by Peacock, the stick symbolized the tool used to unearth the prairie turnip, while the feathers represented turnip leaves.

A 1957 photograph of a Blackfoot holy woman depicts an additional adornment: a bunch of dried, twisted roots tied to the headdress. That photo, Peacock says, sparked her fascination with the prairie turnip.

Despite its name, the prairie turnip (Psoralea esculenta) bears little resemblance to the more familiar root vegetable known as the turnip (Brassica rapa). The latter is not a legume and has a more rounded, smooth appearance than the elongated, scraggly prairie turnip, which resembles a skinny potato.

Historical reports from the 1800s and early 1900s indicate that Plains Indians, especially those living in the more prairie-like regions south of Montana, once cultivated P. esculenta widely. The three tribes of the Blackfoot confederacy—the Piegan, the Blood and the Blackfoot—do not eat the prairie turnip today, but Peacock says the plant's extensive roots in Blackfoot legend and language strongly suggest that it once ranked along with buffalo meat as a vital element in their diet.

Peacock speculates that ceremonies and legends depicting the prairie turnip as sacred may reflect the tribes' need to conserve the plant, which the nomadic Blackfoot may have had difficulty harvesting as they moved from one site to the next. On the other hand, she notes, Blackfoot elders recall that any tribe member could dig up the tuber without restriction.

The vegetable's prevalence in tribal customs could also signify that it held special status in the Blackfoot diet, Peacock suggests.

In an attempt to determine the prairie turnip's dietary significance for the northern tribes, [researchers] analyzed the tuber's nutritional content. Their study found that the leguminous tubers contain about 7 percent protein—much more than potatoes (2 percent) and nearly as much as maize (9 percent). The plant also contains a significant amount of vitamin C—17.1 milligrams per 100 grams of weight. This approaches the vitamin C concentrations in fresh citrus fruits (25 to 30 mg per 100 g). Moreover, they said, a flour made by pounding dried prairie turnips (a common tribal practice) would lose little of its vitamin C during storage unless subjected to moisture.

The analysis suggested that P. esculenta "was widely and regularly used [among tribes of the northern plains] and formed a valuable food resource of high nutritional quality."

Historical accounts from Canadian expeditions in 1857 and 1859 describe women and children harvesting prairie turnips with fire-hardened, slightly curved digging sticks. The tuber's hard, dark skin was easily removed, exposing a white, fleshy interior. Some ate the tuber raw; others boiled it, roasted it, or dried it and then crushed it to a powder.

But scientists still lack definitive evidence of the prairie turnip's place in the prehistoric Blackfoot diet, says Peacock, who maintains that most studies of tribal lifestyles have instead focused on buffalo bones, and occasionally the remains of medicinal plants. To clinch the issue, she proposes that archaeologists undertake an extensive search for the burnt remains of P. esculenta and other pit-roasted plants, since charring would have protected them from chemical or bacterial degradation.

In the meantime, Peacock continues to compile ethnographic data on the prairie turnip. This summer, she hopes to witness her first sun dance and view the full costume worn by the holy woman, replete with headdress and digging stick.