Plant-animal hybrids, vegetable sheep and vegetable lambs, were believed to produce cotton as sheep produce wool and are depicted in the bestiaries, the medieval collections of fact and folklore about real and imaginary animals.
Also known as the lambs of Tartary, these creatures were believed to live in the Asian land of Tartary, which is part of present-day Eastern Europe and Russia.
The origins of this odd belief are almost certainly connected to the arrival of cotton bolls from the East into Western Europe. Since no one in Western Europe had ever seen cotton in its unspun, natural form, they assumed that the bolls were a form of wool.
So, the reasoning went, these strange little ﬂeeces probably came from a miniature plant-animal that produced tiny sheep-fruit that ate the grass under the main plant until the bolls ripened and dropped off.
Further “proof” was found in the root—or rhizome, to be accurate—of the fern species Cibotium barometz, which does vaguely resemble a lamb, complete with a body and four legs, especially when all extraneous material is pared away.
Seen together with a cotton boll by someone who had never before seen either one, the leap could be made to the belief that these items were the body and fleece of a vegetable lamb.
Surprisingly enough, belief in the vegetable lamb lasted well past the Middle Ages. Sir Hans Sloan, member and secretary of Britain’s preeminent organization of scientists, the Royal Society of England, and the founder of the English Natural History Museum, had in his possession a “vegetable lamb of Tartary.”
But Sloan lived in an age of scientific investigation—Sir Isaac Newton was president of the Royal Society at the time—and so the “lamb” was studied. It turned out to be a carefully pared example of the Cibotium barometz rhizome.