Geography 316:  Biogeography     In progress 12/11/2003

The Biogeography of  the California Stinging Nettle (Urtica dioica).
  by Lydia Hase, student in Geography 316  Fall 2003   

Thank you for visiting our site. This web page was written by a student in Geography 316: Biogeography and edited by the instructor, Barbara Holzman, PhD.  All photos and maps are posted with specific copyright permission for the express use of education on these web pages. The students have tried to be as accurate as possible with the information provided and sources and references are cited at the end of each page.


"Love is like dew that falls on both nettles and lilies." ~ Swedish proverb

Species Name: Urtica dioica




















Urtica L.


Urtica L. dioica


Urtica L. dioica gracilis





 Even if I spent a day explaining what the nettle looked like and how the plant can effect you, you will never know it's essence until you encounter it.  And when you do, it will definitely be an experience you will never forget.


Description of Species:  

    The California Nettle or Stinging Nettle is a perennial plant that can grow anywhere from three to nine feet high, growing in stands connected by underground roots.  The plant grows a large main stem and from that leaves grow in pairs opposite each other, making the plant seem somewhat four-sided.  The large pointed leaves (three to five inches long) are slightly heart-shaped at the base, dark green, and deeply serrated.  The flowers, which do not have petals, are generally reddish-brown to greenish-white and are dangling in clusters where the stem and the leaves join.  The flowers bloom from April to October, are either bisexual or unisexual and will produce a single seed, a nutlet, which is small, dry and hard- nonsplitting.  The most distinguishable trait the nettle has is that it is covered with bristly, stinging hairs. 


When the sharp, pointed hairs penetrate skin, they break off releasing an irritating fluid, which consists of many chemicals.  This was originally thought to be formic acid, similar to what ants emit, but recent research has revealed it to be three main chemicals—a histamine to irritate the skin, acetylcholine to bring on a burning sensation, and hydroxytryptamine to encourage the other two (Elliott 1997).  The affected skin is left with a small rash that can last for hours or even days.  The severity depends on the part of the body affected, the length of the contact, the size of the plant and the individual response.   The hairs are generally on the underside of the leaves and on the stem.  The genus name Urtica comes from the Latin verb urere, meaning ‘to burn,’ because of these stinging hairs.  The species name dioica means ‘two houses’ because the plant usually contains either male or female flowers (Taylor 1998), which are either on different branches or different plants altogether.

Nettle reproduces vegetatively and by seeds.  Nettle produces abundant seed.  Plants growing in the shade produce approximately 500 to 5,000 seeds per shoot and plants growing in full sunlight produce 10,000 to 20,000 seeds per shoot (Carey 1995).  Seeds remain on the plant until frost when they fall to the ground.  Seeds are not dormant and can germinate 5 to 10 days after maturity (Carey 1995).

           Close up view of nettle hairs



Distribution and Evolution::


Distribution Map: Urtica dioica

A normal habitat for the nettle is stream banks, the borders of deciduous woodlands, moist sites along streams, on mountain slopes, in woodland clearings, and in disturbed areas.  Which happens to be pretty much everywhere.   Nettle tends to be found in temperate and tropical wasteland areas around the world, many countries have a variety of the plant.   The order Urticales has subdivided itself into six families: Moraceae- the mulberry family, Urticaceae- the nettle family, Cecropiaceae- the cercropia family, Ulmaceae- the elm family, Cannabaceae- the hemp family, and Barbeyaceae.   The Urticaceae family has about 40 genera with 500 species.  These tend to be in America, Asia, Africa and Europe.  The Urtica genus has about 30 species which occur in Europe and North America (Gibbs 1950).   The nettle is native to Eurasia and said to have been brought to North America by English settlers.  Even though the common nettle is now highly known for being in mild and moist soils, they are often found in association with human settlements (Godwin 1956).  So where they might have started in Eurasia, nettles followed humans as we migrated across the world.  Urtica dioica are found nearly everywhere in the United States staying closer to the coasts, but going as far south as Kentucky.  Nettles are less likely to be found in the south.  In the Bay Area there are three native species and two known European species.   Records have shown the Urtica dioica to have been present in interglacials of three different ages, the full-glacial, the late-glacial, and the post-glacial (Godwin 1956).   It has a high altitudinal and latitudinal range in conformity with the likelihood that it was a full-glacial survivor.  Nettle generally grows on deep, rich soils ranging from sea level to 10,000 feet (3,000 m) (Jepson).

The nettle is able to survive through just about anything, however persistent flooding and mowing will kill it.  Nettles occur and produce seed in shady habitats but produces more seed in the full sun.  They love the warmth, but will take the cold.  Seeds will remain on the plant until frost when they fall to ground.  They are not dormant and will germinate five to ten days after its maturity (Carey 1995).   In short the nettle is a weed and will almost never go away.    

 "What is a weed? A plant whose virtues have not yet been discovered" - Ralph Waldo Emerson



Medicinal and Economical Uses:

    Nettle has no competitor, mainly because of the stinging hairs.  Animals will not eat them and with the exception of a few kinds of butterflies, insects hardly pay any attention.  Since they are self-pollinating- they are pretty much free to do as they please.  Considered a nuisance to humans now, they were/are actually a plentiful resource for many things, from clothes to food to medicine.  In folk medicine nettles have been used as a diuretic, to build the blood, for arthritis and rheumatism.  Nettle seeds mixed with wine were supposed to treat impotence.  Nettle has even been used as a contraceptive as a prescribed gypsy remedy.  The man was supposed to line his socks with nettle leaves and wear them for 24 hours before engaging in sex (Elliot 1997).  In Brazil the entire plant has been used for excessive menstrual bleeding, diarrhea, and diabetes (Taylor 1998).  Externally it is used for skin problems.  In the United States the leaf and root are used for different ailments.  The leaf is used as a diuretic, for arthritis, prostatitis, rheumatism, rheumatoid arthritis, high blood pressure and allergic rhinitis.  The root is recommended as a diuretic, for relief of benign prostatic hyperplasia (BPH) and other prostate problems, and as a natural remedy to treat or prevent baldness.  Native Americans once used nettle for making fabrics.   In parts of Europe, fibers from the lanky stems were twisted into rope and woven into cloth until quite recently.  Before World War I, the Germans were harvesting up to 60,000 tons of nettles a year to make soldiers' uniforms (Elliott 1997).  When nettle is boiled it is no longer capable of stinging.  Its leaves can be made into tea, pudding, soup, and in salads- much like spinach leaves.  Eating fresh (or boiled rather) nettle provides an excellent source of vitamin C, calcium, magnesium, and iron. 


ďWe lived upon nettles while the nettles were good.Ē  ~ Traditional English Song



Other interesting issues:

    Once you encounter a nettle you will never forget it.  I remember the first time I was 12, I think, and I was in Germany visiting relatives with my mom and brother.  We were waiting to cross the street and I saw that there was this green plant to the right of me, but I didnít think very much of it.  Until the light turned green and I somehow extended my arm right into it.  As soon as I touched the plant, I quickly brought my arm in and inspected it.  My arm was red and had small bumps.  It didnít exactly hurt; I was more confused than anything.  I did have a burning sensation and I quickly brought it to my momís attention.  She told me about the plant and then got something to cool it. 

 My next encounter was when I was 16, also in Germany, and I was hanging out with my aunt and her husband.  Well for some reason I was riding a tandem bicycle with her husband and I remember getting really annoyed with him.  I was thinking that I would do anything to get out of this situation and go home, or go shopping.  When we stopped to take a break I saw a nettle plant near the trail.  I think I pretended to do some sort of stretch when I just stuck my whole arm into the plant.  My arm was red and surprisingly it still didnít really hurt, it was more irritating.  I complained about it hurt and how I should go and tend to it.  I really just freaked out on him and left.  From that incident stemmed a long running joke with my brother and how I would love to just have nettle around me for situations just like those.


**  In the Hans Christian Anderson story, "The Wild Swans," the 11 brothers of a beautiful princess were trapped by an evil spell in the bodies of swans. The spell could only be broken if the princess made each brother a coat from nettles and didnít utter a word the whole time she was doing it. As one might expect, she succeeded. **


Last nettle note: Urtica is apparently also very efficient in the filtering of metals, minerals and waste materials from contaminated water, storing these substances in its plant fibers and cleansing water supplies. It's excellent for organic waste treatment and as a detoxification system. Many of the materials it collects can be recovered afterward from the dead plant matter.  It's great for composts.





Becking, Rudolf W. 1982.  Pocket Flora of the Redwood Forest.  pp. 208. Island Press Covelo, Ca.


Carey, Jennifer H. 1995. Urtica dioica. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (2003, October). Fire Effects Information System, [Online]. Available:


Elliott, Charles. 1997, January. “Rash Encounters.” Horticulture v 94 pp. 30


Freckmann, Robert W., Hugh H. Iltis  Photographers. Tobert W Freckmann Herbarium, University of Wisconsin-Stevens point. Online: October 28, 2003


Gibbs, R. Darnby. 1950. Botany: An Evolutionary Approch. Philadephia, The Blakiston Company. pp 349


Godwin, H. 1956. The History of the British Flora. Cambridge University Press pp 184


Hickman, James C. 1993. The Jepson Manual; Higher Plants of California. pp. 1083 University of CA press: Berkeley, Los Angeles, London


Lavelle, Mick. 2003, July, 4. Grasping the Nettle; Despite their reputation as a menace, stinging nettles are one of the UK's most important native plants. Essex Chronicle pp.25


Loughrey, Janet. 2001, July, 12.  Homes & Gardens of the Northwest Bio: Flora Stinging Nettle.   The Oregonian


Moore, Michael. Southwest School of Botanical Medicine Bisbee, AZ.  Online: October 28, 2003


Taylor, Leslie. 1998.  Herbal Secrets of the Rainforest.  2nd edition. Prima Publishing, Inc.  Rocklin, CA.  Also available online at


USDA, NRCS. 2002. The PLANTS Database, Version 3.5 ( National Plant Data Center, Baton Rouge, LA 70874-4490 USA.




send comments to

Geog 316 homepage        Back to Geography home page           Back to SFSU homepage