Elisabeth C. Miller Library logo Miller Library Home UW Botanic Gardens Home UW Botanic Gardens Home book graphic

3501 NE 41st Street, Seattle, WA 98195 | (206) 543 0415 | Open: | Library Schedule

Gardening Answers Knowledgebase

Search Results for: Medicinal plants | Search the catalog for: Medicinal plants

Plant Answer Line Question

Keywords: Plant care, Coleus, Medicinal plants

I want to know about Coleus forskohlii a plant of South Africa. What growing conditions does it need, and what are its medicinal properties?


The plant you ask about is Coleus forskohlii (also known as Plectranthus forskohlii) in the family of plants called Lamiaceae. If your growing conditions resemble those of its native range (it grows wild in parts of West Bengal), you may be able to grow this plant.

The article referenced below, entitled "Development of Coleus forskohlii as a medicinal crop", from the Food and Agriculture Organization Document Repository, should give you much information of interest. The document may be found in the online FAO Corporate Document Repository.

Here is an excerpt from the above web document:
Coleus forskohlii grows wild on sun-exposed arid and semi-arid hill slopes of the Himalayas from Simla eastward to Sikkim and Bhutan, Deccan Plateau, Eastern Ghats, Eastern Plateau and rainshadow regions of the Western Ghats in India. Latitudinal and altitudinal range for the occurrence of the species is between 8 degrees and 31 degrees N and 600-800 m respectively. The species was studied for its ecological preferences in its native habitats throughout its distribution range excluding Eastern Plateau, Sikkim and Bhutan. Before the botanical studies were undertaken, the species was studied in the regional floras and herbarium specimens were examined in seven zonal herbaria of the botanical survey of India at Dehra Dun (Himalayan flora), Allahabad (Central India flora), Shillong (northeastern India flora), Jodhpur (Rajasthan flora), Pune (western India flora), Coimbatore (southern India flora) and Port Blair (Andaman and Nicobar group of islands flora), as well as at the Forest Research Institute, Dehra Dun and the Blatter Herbarium in Bombay. Eleven representative ecogeographic areas were selected for habitat and population studies; between 1982 and 1985, 27 botanical trips were made for the purpose. Coleus-growing areas in the Himalayas in Uttar Pradesh were visited every month from April to December, and the other areas were visited at least twice during the blooming period. The following is the summary of the observations made on different populations and habitats of C. forskohlii (Shah 1989).
C. forskohlii is a subtropical and warm temperate species naturally growing at 600-1800 m elevation
The species grows on sun-exposed hill slopes and plateaus in arid and semi-arid climatic zones
The species inhabits loamy or sandy-loam soil with 6.4 to 7.9 pH
The species is herbaceous with annual stems and perennial rootstock

The medicinal uses of this plant have not been evaluated fully for safety. Sloan-Kettering Cancer Center also has useful information about Coleus forskohlii. Here is a brief excerpt: "Very limited data are available concerning the efficacy of forskolin. Most studies performed with forskolin have been human trials; those performed on heart failure and glaucoma are inconclusive."

As with any drug or herbal medicine, you should consult a medical professional if you have questions about its use.

Date 2018-04-11
Link to this record only (permalink)

Plant Answer Line Question

Keywords: Quirky, Catha, Medicinal plants

Recently I found an Ethiopian man and his wife in my front yard. They were picking the reddened leaves on an otherwise green bush/tree. The man explained this was a "cat" or "Chat" tree, the leaves produce a drugged like state when ingested. He asked me if he could harvest the tree,and not to tell any Somalians, Ethiopians, or Eritrean folk about my tree. He also told me that if I lived in Mogadishu I would be a wealthy man with this tree. He ate some leaves in front of me, and I tried a couple, but they were bitter and unpalatable to a westerner like me. I experienced a feeling of empowerment, strength, and mental alertness. Obviously the "Chat Tree" has some relationship to the "Bongo" young Somalians chew on like a cud.

During the worst of the Anarchy in the late 1990s in Mogadishu there was a lot of news footage of the street gangs, high on the plant they were chewing, and armed with machine guns and machetes, creating havoc.

Do you know the history of this tree?
What are the properties that cause the poisoning?
What is the tree`s botanical name?
Should I report the tree`s existence to the authorities?
Can you tell me what I have here?

P.S.-These trees are common front garden bushes that were widely planted in Perth, Western Australia. Next time I see an African hanging out under one of them, I think I will know why!


The chat, or khat tree, is Catha edulis (Celastrus edulis), and the leaves and branchlets have properties that stimulate the central nervous system. In addition to the euphoric or inebriating properties, chewing the leaves can cause irritability, decreased appetite, gastric upset, constipation, and inflammation of the mouth. Habitual use can lead to periodontal disease, and increased risk of esophageal cancer. The active compounds are Alkaloid D-norpseudoephedrine, as well as other alkaloids, and tannins. (Source: Medical Botany: Plants Affecting Human Health by Walter H. Lewis; John Wiley & Sons, 2003, 2nd ed.)

The Handbook of Medicinal Herbs by James A. Duke (CRC Press, 2002, 2nd ed.) indicates that Catha edulis has been used medicinally to treat a great number of ailments, including asthma, depression, diarrhea, glaucoma, and low blood pressure. Use of khat is an ancient, socially acceptable tradition in the Afro-Arabian culture (and became known as a recreational drug in the USA after American soldiers were exposed to its use in Somalia. Khat is subject to legal restrictions in many countries. (Medicinal Plants of the World by Ben-Erik van Wyk; Timber Press, 2004).

As for whether to report the harvesting of leaves from your tree, that would depend on whether khat use is specifically prohibited by law in Australia.

Date 2018-04-11
Link to this record only (permalink)

Plant Answer Line Question

Keywords: Sassafras albidum, Medicinal plants

When and how do I harvest bark from my Sassafras tree to make tea?


I would suggest proceeding with extreme caution, and talking to your physician before endeavoring to make sassafras tea. According to Medical Botany: Plants Affecting Human Health by Walter Lewis (Wiley, 2003), the active component in Sassafras albidum, safrole, is no longer generally regarded as safe. It is toxic to the liver and can cause cancer. There is information on sassafras here from the Natural Medicine Database. A now-unavailable article on the U.S. Food and Drug Administration website included this description of sassafras as a tea ingredient:
"Aromatic sassafras tea, once popular as a stimulant and blood thinner and as a reputed cure for rheumatism and syphilis, causes cancer in rats when taken in large amounts. Oil of sassafras and safrole, major chemical components of the aromatic oil in sassafras root bark, were taken out of root beer more than 30 years ago. And sassafras bark was banned from use in all food. Safrole-free extract, however, is allowed in food."

Although historical sources may discuss the best time to harvest parts of the Sassasfras plant for medicinal uses, I would recommend against using it for this purpose, given the associated health risks. Tyler's Honest Herbal by Steven Foster and Varro Tyler says that the root bark was used as a febrifuge prior to 1512 by native dwellers in Florida. The fact that its reputation for usefulness persists is mainly due to its pleasant aroma and flavor, but the authors make clear that it is unsafe.

You are welcome to come in to the Miller Library and explore our resources on medicinal plants and herbs, but I would not advise you to follow any recipes you might find there.

Date 2018-03-01
Link to this record only (permalink)

Plant Answer Line Question

Keywords: Quirky, Daemonorops draco, Medicinal plants

Someone told me about an herbal remedy called Dragon's Blood which is made of the resin of Daemonorops draco. It's supposed to be good for relief from pain and headaches. Can you tell me more about the plant, including its medicinal uses?


The plant in question, Daemonorops draco, is a type of palm (Family: Arecaceae). Here is the USDA Germplasm Resources Information Network page about this plant.

The common name Dragon's Blood can refer to a number of different plant resins (such as those derived from Dracaena cinnabari, Dracaena draco, and Croton). The product you mention says it is derived from the palm Daemonorops draco. The resin of this plant has a history of use in folk medicine. Cropwatch.org has additional information about the uses the several plants that are called Dragon's Blood, as well as their conservation status. Some of the plants are on the IUCN Red List of Threatened Species (Dracaena cinnabari is listed as vulnerable, as of 2009). This may be of interest to you because often the products you find for sale are not well-regulated, and there may be no way of verifying that the list of plant ingredients is either valid or complete.
Here is an excerpt:
"Few commodity dealers properly distinguish the various botanical origins of Dragon's Blood items, and over-exploitation is starting to threaten some sources."

As for medicinal and other uses of substances called Dragon's Blood, here is more information from Cropwatch.org:
"The term 'Dragons Blood' refers to a product obtained from the resin layer consisting of diterpene acids found on the surface of fruits of the climbing palms of the Daemonorops genus found in SE Asia, and often sold out of Sumatra, Malaya & Borneo. These reddish resinous products (usually encountered as granules, powder, lumps ('cakes'), or sticks ('reed') used in folk medicine as an astringent and for wound healing etc., and in other applications for colouring essential oils red to dark brown, in varnishes, staining marble, for jewelry and enameling work, and for photo-engraving. Mabberley (1998) suggests Dragons Blood was produced originally from Dracaena cinnabari, later from D. draco and more recently from Daemonorops spp.; Zheng et al. (2004) confirm this view and suggest substitutes for Dracaena spp. include Pterocarpus spp., Daemonorops draco and Croton spp."

There is also an article by Jane Pearson published by the Royal Botanic Gardens at Kew (2002) on the uses of Dragon's Blood.
"The term 'Dragons Blood' is interchangeably used to refer to plants from three quite different families: Dracaena cinnabari (Socotra) and Dracaena draco (Canary Islands) in the Dracaenaceae family; the palm genus Daemonorops (Malaysia), and the genus Croton (South America) in the Euphorbiaceae family. [...] Although Daemonorops resin is similar in appearance, its origin and preparation are different to Dracaena resin. The fruits are covered in small imbricate scales through which the resin exudes, forming a brittle, red resinous layer on the outside of the fruits. Collection occurs just before the fruit is fully ripe. [...] Although used in the same way as Dracaena, the powdered form of Daemonorops was used extensively, especially in America, as an acid resist by photo-engravers up until the 1930s. It also appears to be used in both traditional Chinese medicine and Chinese herbal folk medicine. Daemonorops is traditionally used to stimulate the circulation, promote tissue regeneration by aiding the healing of fractures, sprains and ulcers and to control bleeding and pain." [My note: Daemonorops draco is referred to as Xue Jie in Chinese medicine.]

Please note that we are not medical professionals, so if you are considering using a substance which claims to contain Daemonorops draco, you should consult your healthcare provider. However, I can tell you that there are ongoing concerns about contamination of patented herbal remedies. University of Minnesota has information on traditional Chinese herbal medicine and related safety concerns.

Date 2017-05-05
Link to this record only (permalink)

Plant Answer Line Question

Keywords: Medicinal plants, Artemisia

Can you tell me about an herb called Estafiate (I think it's Spanish)? What would the English name be, and how is it used?


There isn't always a straightforward link between a common name and a specific scientific name, but it seems that Estafiate usually refers to Artemisia ludoviciana, possibly the subspecies mexicana, which goes by several different English common names, including white sagebrush, prairie sage, Louisiana sage, and Mexican wormwood. The USDA taxonomy website has information about this plant, as does their general plant database.

Duke's Handbook of Medicinal Plants of Latin America by James A. Duke (CRC Press, 2009) lists Estafiate as Artemisia ludoviciana and several other synonymous names. Its diverse uses include analgesic, antiseptic, and fungicidal but it also has dermatitigenic and carcinogenic properties and is elsewhere (FDA) classified as a poisonous plant. One should never attempt to use a medicinal plant without full medical knowledge and consultation with a health professional! The plant has been used by Native American (Blackfoot, Apache, Cheyenne and other tribes)as well as Mexican practitioners.

Another Spanish common name for the same or similar plant is Ajenjo, which may refer to Artemisia absinthium, which is the same plant from which Absinthe is historically derived. Missouri Botanical Garden has a website with information about this species Artemisia.

Date 2017-05-11
Link to this record only (permalink)

Didn't find an answer to your question? Ask us directly!

Browse keywords

Search Again:

August 01 2017 12:36:01