Geography 316:  Biogeography     In progress  05/22/2005

The Biogeography of  California Jointfir (Ephedra californica)
 

by Adam Ganser, student in Geography 316  Spring 2005

Thank you for visiting our site. This web pages 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.

Species Name: Ephedra californica

 

Kingdom:  Plantae
Subkingdom:  Tracheobionta – vascular plants
Superdivision:  Spermatophyta – seed plants
Division:  Gnetophyta
Class:  Gnetopsida
Order:  Gnetales
Family:  Ephedraceae
Genus:  Ephedra
Species: 
Ephedra californica

Common name:  California jointfir

  J.S. Peterson @ USDA-NRCS PLANTS Database

Description of Species:

Ephedra californica, commonly known as California Jointfir, is a shrubby desert perennial gymnosperm.   The plant is densely branched with erect stems and can grow up to two meters tall.  Twigs are whorled at nodes, yellow-green when young, aging to a gray-brown color.  Twigs also have distinct lateral grooves running along full length.  E. californica has very reduced leaves (less than 3 mm), occurring three per node, with whitish margins that wear away, leaving thickened brown bases.  Pollen cones occur 1-3 per node and are less than 9 mm in size.  Seed cones are less than 12 mm in size, and each generally produces one seed.  Pollen and seed cones are found independently on their own respective plants, a condition called dioeciousness (Hickman, 1993).

Natural History:

Ephedra californica is very drought tolerant, which is evident by looking at its morphology.  The leaves are very small, so they do not transpire too much water and desiccate the plant.  The stems are green and photosynthetic to compensate for the loss of leaf area available for gathering the sun’s energy (Cutlar, 1939). 

Since E. californica is a gymnosperm, it has no actual flowers, but instead it produces pollen and seed cones, with one sex of cones per plant.  This strategy ensures that plants will cross-pollinate, since an individual plant cannot pollinate itself (Judd, 2002).   Ephedra are wind pollinated and only reproduce during years where there is ample rainfall.  The plants may go for years without setting seed, but when they finally do reproduce, they release an enormous amount of seed all at once.  And it is not just one plant that reproduces, but most to all of the plants will reproduce during these rain events.  After reproducing, the seeds remain dormant in the soil for several years, even if heavy rains occur during that dormant period.  After the dormant period, the seeds will germinate with the next heavy rain (Meyer,2005).

This method of reproduction and seed dispersal is a reflection of the resource limitation, particularly water, that Ephedra californica faces in its natural habitat, where there is no rain for more than half of the year.  Also, the sandy soils they live on have very little water holding capacity.  Ephedra have evolved a strategy for taking advantage of the precious and unpredictable heavy rainfall.  Their strategy of establishing a large seed bank during a time of water availability is commonly seen in different arid climate plant species, particularly in Mediterranean climates (Gurevitch et. al, 2002).

Evolution:

Ephedra is the only genus in the family Ephedraceae within the order Gnetale.  Therefore, much of the relevant evolutionary and natural history of Ephedra californica is specific to its taxonomic order, Gnetales.  There are five major extant lineages of spermatophytes, or seed plants: cycads (Cycadales), ginkos (Ginkgoales), conifers (Coniferales), gnetophytes (Gnetales), and flowering plants.  Ephedra is one of three extant genera of the Gnetale order.  The other two genera, Gnetum and Welwitschia, are truly bizarre and will be discussed later (Judd, 2002). 

The fossil record for gnetophyte pollen grains dates back to the Triassic (~200-245MYA), although the most modern groups diversified within their clade during the mid-Cretaceous (~100MYA) along with the angiosperms (Judd, 2002 and Campbell 2002).  The evolutionary history of the Gnetales is not entirely clear.  Existing fossil records, systematic data, and molecular studies have all been utilized in determining the correct phylogenic placement of the Gnetales in the evolutionary tree. Researchers have compared physiological and morphological features of Gnetales  to other plants, finding they are similar to both gymnosperms and angiosperms (Judd, 2002).  In fact, the Gnetales have played a pivotal role in modern botany and phylogenetics, because of their intermediate placement between gymnosperms and angiosperms.  The dominant theories in Twentieth Century botany of angiosperm evolution use Ephedrales as a reference point for comparison of the two major plant lineages (Friedman, 1996).

Gnetales are sometimes linked together with angiosperms in a group called anthophytes because they both have vessels in their wood, flower-like structures, and double fertilization (Friedman, 1996).  However, some molecular studies do not support the anthophytes as a clade, instead linking the Gnetales with the conifers (Chaw et. al., 2000).  Gnetales also do not have their seeds enclosed in an ovary, an angiosperm character, which also supports their close relation to the conifers (Friedman, 1996). 

Other studies examining ribosomal DNA support the conifers as a monophylitic clade (without Gnetales nested within), with the Gnetales being more genetically similar to the angiosperms (Rydin, 2002).   The conflict is still not definitively resolved, and it could be possible that Gnetales are not very closely related to either angiosperms or conifers.  Some believe that molecular data may not be able to completely resolve the question and that fossils need to be taken into account more to fill in the gaps in the hypotheses (Donoghue and Doyle 2000; Frohlich and Parker 2000).  The following trees in Figure A show the two possible placements of Gnetales in evolutionary history.

    Figure A: Possible cladograms for Gnetale evolutionary placement

(Friedman & Floyd, 2001)

Distribution::

Figure B: World distribution of the Genus Ephedra

(Cavaney, 2001)

The genus Ephedra can be found in the arid and semiarid regions of Asia, Europe, northern Africa, western North America, and South America (see map fig. B).  They can grow from sea level to as many as 5000 meters high in the Himalayan and Andes mountains (Price, 1996).

Ephedra thrive in arid to semi-arid environments species have shown distributional patterns where the male plants are located on dryer slopes, while females are located in flatter surfaces where water runs and settles.  This strategy allows for males to utilize their limited water resource for pollination, while the female plant is situated in a place where it can produce seed, a more resource intensive act, and have access to more water for a longer period of time than the male (Meyer, 1995).                                                                                                           

Of the approximately 40 species of world Ephedra, 12 species are found in North America, ranging from the southwestern U.S. to the central plateau of Mexico (Caveney, 2001).  Ephedra californica is found scattered in arid grassland, chaparral, and creosote bush scrub in central to southern California as well as in western Nevada and down into Baja California (Hickman, 1993). 
  Archives, University and Jepson Herbaria, University of California, Berkeley

 The genus Ephedra, commonly known as Mormon Tea, is found throughout the semiarid regions of western North America, often locally codominant with creosote bush (Larrea spp.), blackbrush (Cercocarpus spp.), shadscale (Atriplex spp.), and various species of sagebrush (Artemisia spp.) (Meyer, 1995).  The adjacent figure shows the distribution of E. californica in California.
   

Other interesting issues:
Ephedra has long been used for the medicinal qualities that its stem extracts contain.  The most commonly known extract is a phenylethylamine alkaloid called ephedrine.  Almost all commercial applications of ephedrine use derive from the Eurasian Ephedra species.  The most comprehensive documentation of the use of ephedrine comes from the drug Ma-huang, which has been used in Chinese medicine for more than 5000 years for treating fever, nasal congestion, and asthma.  It was also used in the New World as a treatment for venereal disease, although its efficacy is strongly doubted.  It is also a good respiratory sedative and cough remedy (Cavaney, 2001). 

New World species of Ephedra do not contain significant amounts of ephedrine alkaloids.  However, several nitrogenous secondary compound known to stimulate neuroactivity, like nonprotein amino acids with cyclopropyl ring structures and tryptophan derivatives, have been found in the stems of American Ephedra, which might explain why the plant has been used so extensively in New and Old World traditional medicine.  In at least one study, Ephedra californica was found to contain traces of pseudoephedrine (Cavaney, 2001).

Ephedrine use is relatively new to western medicine, but it has already earned the dubious distinction of being banned in the U.S.  Ephedrine has been brought to the public eye in recent years with the deaths of several athletes whose autopsies found high levels of ephedrine in their blood.  On April 12, 2004 the sale of dietary supplements containing ephedrine were made illegal.  The action was the first time that the FDA has taken formal action stop sale of a dietary supplement ingredient since the passage of the Dietary Supplement Health and Education Act in 1994 (Rados, 2004).

As mentioned, ephedrine has been used in moderation for thousands of years, but recently the drug has been marketed as an appetite suppressant and athletic performance and energy enhancer, leading some to use the drug in excess.  The FDA found that dietary supplements containing ephedrine show only short-term weight loss effectiveness.  They also found that the drug raises blood pressure, stressing the circulatory system and leading to more serious health problems like cardiac arrest and strokes.  The ban is in effect for dietary supplements like ephedra, ma huang, sida cordifolia, and pinellia.  The ban does not pertain to traditional Chinese herbal remedies, herbal teas regulated as conventional food, and drugs that contain chemically synthesized ephedrine (Rados, 2004). 

Bibliography
Campbell, Neil A. and Jane B. Reece. 2002. Biology, 6th Ed. San Francisco: Benjamin Cummings

Caveney, Stanley, David A. Charlet, Helmut Freitag, Maria Maier-Stlote, and Alvin N. Starratt. 2001. “New observations on the secondary chemistry of world Ephedra.” American Journal of Botany 88(7): 1199-1208.

Caveney, Stanley et. al. 2001. Distribution of World Ephedra. This map was constructed mainly from data provided in Hunziker (1949), Freitag and Maier-Stolte (1989, 1993, 1994) , Zhang, Tian, and Lou (1989) , and Stevenson (1993) . The distribution of Ephedra in east Asia extends north of Korea to the Sea of Japan

Chaw, Shu-Miaw, Christopher L. Parkinson, Yuchang Cheng, Thomas M. Vincent, and Jefferey D. Palmer. 2000. “Seed plant phylogeny inferred from all three plant genomes: monophyly of extant gymnosperms and origin of Gnetales from Conifers.” Proceedings of the National Academy of Sciences of the United States of America 97(8): 4086-4091.

Cutlar, Hugh Carson. 1939. “Monograph of the North American species of the genus Ephedra.” Annals of the Missouri Botanical Garden, 26(4): 373-424,426,428.

Donoghue, M. J. and J. A. Doyle. 2000. “Demise of the anthophyte hypothesis?” Curr. Biology 10:106-109

Friedman, William E. and Sandra K. Floyd. 2001. “Perspective: the origin of flowering plants and their reproductive biology – a tale of two phylogenies.” Evolution 55(2): 217-231.

Frohlich, M. W. and D. S. Parker. 2000. “The mostly male theory of flower evolutionary origins: from genes to fossils.” Systematic Botany 25:155-170.

Gurevitch, Jessica, Samuel M. Schneider, and Gordon A. Fox. 2002. The Ecology of Plants. Sunderland, MA: Sinauer Associates, Inc.

Hickman, James C. Ed. 1993. The Jepson Manual: Higher Plants of California. Berkeley and Los Angeles, Ca: University of California Pre

Judd, Walter S. 2002. Plant Systematics: A Phylogenetic Approach, 2nd Ed. Sunderland, MA: Sinauer Associates, Inc.

Meyer, Susan E. 1995. Ephedra. Provo, UT: USDA Forest Service, Rocky Mountain Research Station.

Price, Robert A. 1996. “Systematics of the Gnetales: a review of morphological and molecular evidence.” International Journal of Plant Sciences 157(6) Supp: Biology and Evolution of Gnetales: S40-S49.

Rydin, Catarina, Mari Kallersjo, and Else Marie Friist. 2002. “Seed plant relationships and the systematic position of Gnetales based on nuclear and chloroplast DNA: conflicting data, rooting problems, and the monophyly of Conifers.” International Journal of Plant Science. 163(2): 197-214.

University of California and Jepson Herbaria. (2005). Distribution of Ephedra californica. [Online]. Available: http://ucjeps.berkeley.edu/cgi-bin/get_JM_treatment.pl?184,185,187 [3/20/05]

USDA-NRCS. 2005. The PLANTS Database [Online]. Available: http://plants.usda.gov National Plant Data Center, Baton Rouge, LA 70874-4490 USA.[4/20/05]

 
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