Short answers, pulled from the story.
Rye (Secale cereale) is a grass cultivated as a grain, cover crop, and forage crop, grown principally in Eastern and Northern Europe extending into Russia. It is a member of the wheat tribe Triticeae, which also includes barley and wheat. In 2023, world production reached 12.7 million tonnes, with Germany producing 25% of the total.
Rye likely arrived in Europe as a secondary crop through a process called Vavilovian mimicry, hitchhiking as a minor admixture in wheat fields before being cultivated in its own right. Evidence from Tell Abu Hureyra in northern Syria suggests systematic cultivation as far back as around 13,000 years ago. Domesticated rye appears in Neolithic sites in Asia Minor and then in Bronze Age contexts in central Europe, roughly 1800-1500 BCE.
Ergotism is a disease caused by consuming rye infected with the ergot fungus, producing convulsions, miscarriage, necrosis of digits, hallucinations, and death. Rye is highly susceptible to ergot, and damp northern regions that relied on rye as a staple food suffered periodic epidemics historically. Modern grain-cleaning and milling have largely eliminated the risk, though it persists where food safety practices break down.
Triticale is a hybrid cereal developed from crossing wheat and rye, combining beneficial qualities of both parent crops. Plant breeders began this work in Germany and Scotland in the 19th century, with major progress from the 1950s onward. Modern triticales are hexaploid, carrying six sets of chromosomes, and are produced in millions of tonnes annually worldwide.
The Roggenwolf, or rye wolf, is a carnivorous corn demon from European folklore, described as a field spirit shaped like a wolf that steals and feeds on children. Farmers traditionally left the last grain heads in the field as a sacrifice for agricultural spirits. The scholar Carl A. P. Ruck connected the legend to ergot-infected grain, arguing the folklore preserved cultural memory of rye's most dangerous disease.
A 100-gram portion of raw rye provides 338 kcal and is a rich source of dietary fiber, B vitamins including thiamine and niacin at 25% of the Daily Value, and minerals including manganese at 130% of the Daily Value. Health Canada and the U.S. Food and Drug Administration have recognized that at least 4 g per day of rye beta-glucan or 0.65 g per serving of soluble fiber can lower blood cholesterol levels. Eating whole-grain rye also improves blood sugar regulation.