As many of you know, I am Dr. Jacqueline Soule – but the doctorate is in Botany, not medicine. That doesn’t stop people from asking me health questions, if anything, it elicits more!

Everyone has heard of some wonderful herb that is going to cure all their woes, and they want to ask me about it. And here we get to a real dilemma, because over 90 percent of all drugs used today were once a herbal medicine.  Later the compounds were extracted from the plants, and the compounds purified and dosages standardized.



Doctrine of Signatures

For over 2000 years Old World peoples followed the “Doctrine of Signatures.” Originally written down by the Greeks, the Doctrine of Signatures is based upon the belief that all plants have a sign or “signature” upon them, telling us humans the use for the plant.


Example – a plant with a kidney-shaped leaf must be good for the kidneys.  Maybe it is not the leaf, perhaps it is the root but since the root is hidden underground, the plant had to send up a leaf to let us know what it was good for. The persistence of the belief in the Doctrine of Signatures for all these centuries is due to the fact that many of the plant medicines discovered using the Doctrine do work!


Saw Palmetto

The saw palmetto (scientific name: Serona repens) has been variously reported as an herb used as an aphrodisiac, diuretic, and a cure for prostate problems. The “signature” was seen over 400 years ago by Spanish explorers when they found the plants in Florida. The plants have long, stiff young leaves, not yet unrolled which point skyward like a phallus, plus the rounded fruits cling to either side of a stalk, looking like testes. The use is obvious if you follow the Doctrine of Signatures.


Saw Palmetto Testing

Centuries passed.  Now we have the scientific method and with some medical testing – we discover that saw palmetto can work!  Some types of prostate problems do respond to extracts of saw palmetto.

More than half of men aged 50 and older experience some symptoms related to enlargement of the prostate gland. Saw palmetto extracts can reduce symptoms, via an anti-inflammatory effect that appears to target prostate cells alone, reducing prostate swelling, and reducing urinary tract complaints associated with swollen prostate. Since reduced prostate pain and swelling may result in increased feelings of amorousness, “aphrodisiac” qualities may be seen. If you suspect prostate problems, you must be evaluated by a physician to rule out cancer.

The leaves of creosote bush are almost lung-like. Photo courtesy of Keir Morse.
Creosote Bush

Here in the Southwest, Spaniards “discovered” the creosote bush (Larrea tridentata) and promptly brought it into their medicinal repertoire. It has been used for over 300 years to treat arthritis and asthma. The “signature” is that the leaves that are split almost in two, looking like two lungs joined by the trachea.

Creosote Testing

Leaves of creosote contain liposygenase and cyclooxygenase inhibitors, no different from manufactured chemicals now used by physicians to treat asthma and arthritis. The problem is that these compounds can cause also liver damage. Powdered leaves taken internally have caused liver damage, while teas appear to be less toxic.


Use Wisely

As we see from these two examples – herbs can help us, but they also can harm. The average human life-span used to be about forty years. Perhaps it would have been longer if they could have done what we can today; combine the rich lore of the past with the modern chemical analysis laboratory, to find herbs that can truly help us.


soule-gardening-southwestIf you live in Southeastern Arizona, please come to one of my free lectures. Check our events page for locations and times. After each event I will be signing copies of my books, including Father Kino’s Herbs: Growing and Using Them Today. Note – This link is to Amazon and if you buy the book there I will get a few pennies.

© Article is copyright by Jacqueline A. Soule. All rights reserved.  I receive many requests to reprint my work. You may use a short excerpt but you must give proper credit, and must include a link back to the original post on our site. No using photos!


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