GARDENING : A LESSON IN PLANTS AND FERTILITY.

Byline: Joshua Siskin

Every subject under the sun can be found in the Bible - even aphrodisiac and fertility-enhancing plants. In Genesis, Reuben goes into the wheat fields at harvest time and finds mandrake plants, which he brings back to his mother, Leah.

Immediately, Rachel, who has yet to bear a child, asks Leah - who already has four sons - for some of her mandrakes. (Leah and Rachel are sisters, and both are wives of Jacob.) When Leah declines the request, Rachel says that she will allow Leah to spend the night with Jacob - although Rachel was supposed to be with him then - in exchange for some of the plants.

The exchange is made. That night, Leah conceives. And, the next time Rachel's name is mentioned, she, too, has become pregnant.

Mandrakes (Mandragora officinarum) are mentioned one other time in the Bible, in the Song of Songs love poem: ``The mandrakes give a fragrance, and at our gate are all manner of pleasant fruits, new and old, which I have laid up for thee, O my beloved.''

The mandrake is native to the Mediterranean and produces sweet-smelling, yellow fruit the size of plums. It has rosetted leaves and a growth habit similar to that of the English primrose. Because its large taproots resemble the human form, it was thought to stimulate the process of conception.

Josephus, who documented everyday life in Israel during the time of the Romans, said that a certain dread was also associated with the mandrake. No one who valued his life would actually pull a mandrake out of the ground; instead, a dog would be tied to the plant and, upon pulling it out, would instantly die.

To this day, certain plants are touted as reproductive wonder drugs. Puncture vine (Tribulis terrestris) is a prostrate weed that Southern California gardeners may occasionally encounter. It has decorous pinnate leaves and butter yellow flowers. It also has thorny fruits which puncture bicycle tires and cause severe wounds to animals. Oh yes, it also is supposed to increase the potency of men and the fertility of women.

It is generally held that the element most often lacking in men - that has an effect on potency - is zinc. For this reason, men who want lots of children should grow sunflowers in their gardens, since the seeds of this native American plant are zinc enriched.

When a woman has difficulty becoming pregnant, the problem could be a mineral imbalance. It's possible that too much copper, in relation to zinc, is present in her system. Almonds, avocados, grapes, mushrooms and pecans have a high copper-to-zinc ratio and, in the opinion of some, should be avoided by women who have tried but failed to conceive.

One of the most fascinating new areas of research concerns the effects of phytoestrogens, which are estrogen hormones found in plants, on fertility. Phytoestrogens are weaker than natural estrogen and are found in herbs (garlic, parsley), grains (wheat, rice), vegetables (beans, soybeans, carrots, potatoes), fruits (dates, pomegranates, cherries, apples) and coffee.

An Australian study found that sheep that had grazed on phytoestrogen-rich clover suffered from infertility. A recent review of such studies by scientists at the Tulane/Xavier Center for Bioenvironmental Research drew the following conclusions: ``It may be that plants make phytoestrogens as a defense mechanism to stop or limit predation by plant-eating animals. To avoid predation, plants produce compounds (phytoestrogens) that limit an herbivore's reproduction. Thus, the predator's population decreases and more plants prosper.''

Despite these fertility-dampening effects, consumption of phytoestrogens may also have certain benefits. From the same Tulane/Xavier review, we learn that ``Asian populations that eat large amounts of soy products - which contain high levels of phytoestrogens - have lower rates of hormone-dependent cancers (breast, endometrial) and a lower incidence of menopausal symptoms and osteoporosis than do Westerners, who don't traditionally eat these products. Asian immigrants to Western nations also increase their risks of these maladies as they westernize their diets to include more protein and fat and reduce their fiber and soy.''