Sauer - 1993 - Historical geography of crop plants, a select rost

Monocots 213
palustris), is an annual with a wide native range; it is currently an incipient
domesticate as a grain crop.
The native range of Z. aquatica, sensu lato, extends from Idaho and Manitoba
to the maritime provinces of Canada and New England and southward to Texas
and Florida. Its main habitats are shallow lakes and slow-moving streams with
silty or muddy bottoms. It is commonly associated with cattails and water lilies.
Along the seaboard, it sometimes grows in brackish marshes by river mouths.
Suitable habitats are highly disjunct, and wildrice, like most aquatic plants,
is dependent on bird dispersal for its wide range. Wildrice is a regular food
of waterfowl and various other birds. It is also attractive to moose and muskrat.
As in all cereal grains, the wildrice in natural stands has shattering inflorescences.
Seed is not buoyant, but sinks to the bottom and remains dormant
over winter or over several winters. Upon germination, ribbon-like leaves float
to the surface in spring, followed in summer by the emergent stalks, which
usually reach about 1 m, sometimes as much as 3 m in height.
Indian peoples began harvesting Zizania prehistorically, especially in the
northern glaciated terrain where it is most abundant. Traditionally, two people
harvested the ripening grain from a canoe, one propelling the canoe while the
other used sticks to bend the inflorescence over and gently dislodge the ripe
grain. Most of the grain escaped harvest, even if a stand was reworked several
times, and Indian exploitation probably had no more bad effects than waterfowl
feeding; neither did if result in domestication. By 1900, wildrice bought from
Indian gatherers had entered commerce as an expensive delicacy. Ingenious
harvesting machines were invented, mounted on boats or pontoons. In both
Canada and the U.S., exploitation was generally limited by government regulation,
and much of it remained in Indian hands. There have, of course, been
many attempts to expand the stands. During the 1930s, for example, the Indian
branch of the U.S. Civilian Conservation Corps carried out extensive seeding
attempts. As a rule, attempts to manage and expand natural stands had little
effect, one way or the other. The species already occupied all suitable habitat,
and artificial planting was a waste of seed.
In the 1950s in northeastern Minnesota, a different approach was begun,
namely, planting of wildrice in artificial paddies separate from the natural
stands. The planting stock was still of the wild, shattering type, and the stands
regenerated annually from the seed that escaped harvest.
Zizania grain at maturity has a remarkably high water content, usually over
40% by weight, and remains viable for only a few days if exposed to air drying.
Grain harvested for consumption is usually promptly killed in the early stages
of processirig by drying and parching. Saving grain for artificial planting
requires storage in cold water. This peculiar adaptation, the need for Zizania
grain to be kept constantly in cold water to remain viable, has been a real
obstacle to domestication, which has not yet been overcome. Even when the
crop is grown in an artificial paddy, farmers have commonly continued to rely
on natural reproduction from shattered seed stored over winter in the mud. A
crucial process in the domestication of other grain crops was therefore blocked: