Wild Yam belongs to the family Dioscoreaceae, the true Yam family, and is the only native Yam species widespread in eastern North America. The genus Dioscorea is named after the first-century Greek physician and botanist Pedanius Dioscorides (born c. 40 A.D.), author of De Materia Medica, a five-volume guide describing medicinal plants and other substances, which became a major reference on medicines for more than a thousand years. The specific epithet villosa means “hairy” in Latin and refers to the pubescence, or fine, short hairs, found on some forms of the plant.
The slender vines of Wild Yam wrap themselves around supporting vegetation and can range in length from three to eighteen feet. The mingling of its leaves with those of the plants it has entwined can make it even harder to spot. Despite its inconspicuousness, it is quite common along some portions of the GAP, occurring in moist woodland borders and forest edges, especially where deciduous forests transition to open areas or stream corridors. It grows best in partial to full sun with moist to well-drained soil, favoring sandy to rocky loam. It tolerates considerable shade but grows most prolifically at woodland edges receiving several hours of direct sun. The tiny, inconspicuous pale green to cream-colored flowers bloom from early June through July, with the male and female flowers occurring on separate plants. The underground portion consists of long, horizontal, branching rhizomes growing twelve to eighteen inches below the soil surface. The tough, woody rhizomes are pale tan externally, whitish internally, with a distinctly bitter, slightly acrid taste. This is the medicinally active portion of the plant.
According to ethnobotanical records the Meskwaki people who lived in the great Lakes Region used the root of Wild Yam to relieve menstrual pain and ease childbirth. Wild Yam also figured prominently in the Eclectic botanical tradition of the 19th and early 20th centuries. It has its own entry in King’s American Dispensatory (1898), the bible of the Eclectic Movement, which calls it “a specific in bilious colic” and lists it as a treatment for “nausea and colicky pains,” “paroxysmal abdominal pain,” “sharp abdominal pain, made worse by motion,” and other assorted ailments.
Wild Yam entered modern pharmaceutical history when Russell Marker, a Penn State chemistry professor, figured out a process (later called the “Marker Degradation”) for converting plant steroids known as sapogenins into progesterone, the hormone essential for pregnancy and menstrual regulation. He first worked out the process on sarsasapogenin from sarsaparilla, and in 1940 he applied it to diosgenin, a steroid he extracted from Wild Yam roots. He soon found that the Wild Yam (Dioscorea villosa) yielded too little diosgenin to make full-scale production of progesterone feasible. Marker spent the next few years looking for an alternative, testing over 400 plants, until he discovered a species of Yam growing in Mexico with enormous roots weighing up to 200 pounds each that were rich in diosgenin. In 1942 he smuggled a 50-pound root out of Mexico back to his lab at Penn State and was able to extract diosgenin in significant amounts. He tried to sell his discovery to American pharmaceutical companies, but they were not interested. In 1944 he and two partners, Emeric Somlo and Federico Lehmann, founded their own company in Mexico—Syntex, S.A.—which by the late 1940s was mass-producing progesterone from Mexican Yams, crashing the price from roughly $80 a gram down to a few cents per gram over the following decade. This cheap, Yam-derived progesterone became the essential raw material for two major pharmaceutical breakthroughs: cortisone (via an oxidation process) and oral contraceptives.
The contraceptive angle was pursued by Syntex chemist Carl Djerassi, who in 1951 used diosgenin-derived progesterone to create a synthetic compound known as norethindrone, which would become the active ingredient in the first practical birth control pills. Syntex, however, couldn’t sell drugs in the U.S. It was a Mexican company that produced bulk steroids. It had no labs or factories in the States and no American sales operation, so it licensed norethindrone to Parke-Davis, a well-known American company, which won FDA approval in 1957 to sell it as Norlutin for menstrual disorders. Fearing a boycott of its other products by Catholics, many of whom opposed birth control, Parke-Davis refused to market it as a contraceptive. Syntex’s norethindrone finally reached the market as a contraceptive in 1962 as Ortho-Novum, made by Ortho Pharmaceutical, a division of Johnson & Johnson. In 1964 Syntex was able to market its own version of the Pill, known as Norinyl. By then Parke-Davis had realized that no significant Catholic boycott was happening and began selling its own version of the Pill. Syntex continued to supply much of the bulk steroid for the industry and its Yam-based chemicals ended up in pills that carried other companies’ names. By 1967 more than 12.5 million women worldwide were using the Pill, and by 1970 seven American companies were making it.
Wags have suggested that the Wild Yam, the humble plant that grows along the GAP, was responsible for the Sexual Revolution that began in the late 1960s. This may be an exaggeration, but it remains a fact that the Wild Yam deserves credit as the unlikely root ingredient that made cheap, effective birth control pills possible. Aging GAPers who lived through the beginning of the Sexual Revolution—assuming they have good memories of it—may want to give the Wild Yam a nod of appreciation if they do happen to stumble upon it.
 |
| Wild Yam |
 |
| Wild Yam |
 |
| Wild Yam |
