Ephedra is the sole genus in Ephedraceae Dumortier 1829, which many authors designate as the sole family in Order Ephedrales Dumortier 1829. Huang et al. (2005) find that phylogenetics in the genus are best predicted by geography, with distinct groups in the Americas, Asia, and the Europe-Mediterreanean region. Stevenson (1993) notes that the American species, at least, are highly distinct, and that "putative hybrids reported and described by Cutler (1939) appear to be products of singular events."
The family has been around at least since the early Cretaceous, at which time it contained at least one genus (Ephedrispermum) in addition to Ephedra (Rydin et al. 2006). The surviving species seem to be a relict group that happens to have done well during the climate changes, principally the development of very extensive semiarid habitats, that have swept the globe since the Oligocene.
Currently, this treatment contains accounts for the following species:
For the following taxa I have no information and have not prepared accounts yet. The links take you to the respective IUCN red list pages for each species:
Dioecious (rarely monoecious), erect, procumbent or climbing shrubs or vines. Bark grey to reddish brown, cracked and fissured, often fibrous. Branches much branched, photosynthetic, yellowish green to olive-green when young, round, finely longitudinally grooved, jointed, internodes 1-10 cm. Roots generally fibrous. Leaves mostly not photosynthetic; opposite or in whorls of 3; simple, scalelike, connate at base to form a sheath, generally ephemeral; resin canals absent. Cotyledons 2. Pollen cones 1-10 in whorls at nodes, each compound cone composed of 2-8 sets of opposite or whorled membranous bracts, proximal bracts empty, distal bracts each subtending a small cone composed of 2 basally fused bracteoles subtending a sporangiophore bearing 2-10(-15) sessile to long-stalked, bilocular, apically dehiscent, pollen-producing microsporangia. Pollen prolate, with 6-12 longitudinal furrows, not winged. Seed cones 1-10 in whorls at nodes of twigs, each compound cone sessile or on short to long peduncle, composed of 2-10 sets of overlapping, opposite or whorled, membranous or papery to fleshy bracts, proximal bracts empty, most distal bracts subtending 1 axillary cone composed of a pair of fused bracteoles enclosing a single-integumented ovule with integument projecting as tube from bracteole-envelope, envelope forming a leathery "seed coat" that is shed with seed. Seeds 1-2(-3) per compound seed cone, yellow to dark brown, smooth or furrowed. Wood ring porous, lacking resin ducts, with wide multiseriate rays and vessels in older stems (Stevenson 1993, Fu et al. 1999).
For proper identification of Ephedra, fruiting and flowering material is essential. Many sterile specimens of various taxa look alike (Ali and Qaiser 1987).
The various species are distributed as follows:
Their habitats are all described as dry, rocky and/or sandy. A few species occur in grasslands, and for a few species, habitat is not specified.
One species occurs in Argentina and Chile, from Tierra del Fuego to 42° S.
Two species occur in North Africa, one of which also occurs in SW Asia (Saudi Arabia, Kuwait, Israel) and Cyprus.
Twelve species are in the USA (Arizona, California, Colorado, Nevada, New Mexico, Oklahoma, Oregon, Texas, Utah, Wyoming) of which 5 species also occur in Mexico (Baja California Norte, Chihuahua, Coahuila, Nuevo León, San Luis Potosí, Sonora).
The remaining 21 species are Eurasian, with focal areas in central Asia (18 species) and around the Mediterreanean (4 species, plus the North African ones). These break out according to country as follows:
The New World species mostly occur at elevations of below 2000 m, with a few species reaching as high as 2300 m. The Eurasian species show a much greater elevation range, from sea level to 5300 m (E. gerardiana, the highest gymnosperm species). E. intermedia probably has the greatest elevational range of any single gymnosperm species, ranging from 100 to 4600 m elevation across its vast range.
For most taxa I have found no records of specimen size.
I have found no records of specimen age.
No record of use for any species. Although Ephedra does produce growth rings, which in most cases are of roughly annual frequency, the genus has not been used in dendrochronology.
Throughout its distribution it is used by native cultures for a variety of medicinal purposes, including cough medicines, an antipyretic, an antisyphilitic, a stimulant for poor circulation, and an antihistamine. These uses are based on the presence of tannins and alkaloids, particularly ephedrines (Stevenson 1993). In recent times, it has achieved widespread popularity as an 'herbal medicine' used in weight-loss preparations and 'energy' preparations (both uses due to its stimulant effects) and cold and allergy medications (due to the presence of the bronchodilator ephedrine) (Herbal Information Center. [no date]).
The old world species contain variable amounts of ephedrine; curiously it is not present in the New World species, and the psychotropic properties ascribed to "Mormon Tea" and its relatives remain unknown. The oldest drug produced from Ephedra is the Chinese ma-huang, which has been used in Chinese medicine for over 5000 years to treat fever, nasal congestion and asthma. Ma-huang is widely sold in the western world, usually with dubious claims as to its curative values (literature review by Caveney et al. 2001). Ephedra has also been used in the synthesis of methamphetamine (Andrews 1995).
See the species accounts.
Named from the "Greek ep-, upon, and hédra, seat or sitting upon a place; from the ancient name used by Pliny for Equisetum; the stems resemble the jointed stems of Equisetum, the segments of which appear to sit one upon the other" (Stevenson 1993).
"In Ephedra the habit varies greatly even in the same species. Dwarf bushes a few inches high are common (E. distachya, etc.). E. distachya and other species are also represented by tall bushes up to 6 ft. in height, with virgate branches. E. triandra may attain the habit of a small tree with a trunk a foot in diameter. Climbers of the "weaver" type with slender pendent branches are found in E. altissima and E. fragilis: these and other species include forms in which the branches are prostrate.
"Most species, especially in loose soils, spread by means of branching rhizomes which arise from buried nodes of the erect stems; they thus exert a binding effect upon the soils in which they grow. In E. alata, growing in the sand dunes of the Areg formation of Algeria and Tunis, the rhizomes attain a length of several metres and form efficient sand binders. Erect shoots of the normal type arise from the axils of the younger leaf-sheaths. When these shoots are isolated by the breaking or decay of the parent rhizome they differ from seedlings only in the absence of tap-roots" (Pearson 1929).
Ali, S.I. and M. Qaiser (eds.). 1987. Flora of Pakistan. http://www.efloras.org.
Andrews K.M. 1995. Ephedra's role as the precursor in the clandestine manufacture of methamphetamine. Journal of Forensic Science 40: 551-560.
Caveney, Stanley, David A. Charlet, Helmut Freitag, Maria Maier-Stolte and Alvin N. Starratt. 2001. New observations on the secondary chemistry of world Ephedra (Ephedraceae). American Journal of Botany 88:1199-1208. http://www.amjbot.org/cgi/content/full/88/7/1199, accessed 2006.10.18.
Cutler, H.C. 1939. Monograph of the North American species of the genus Ephedra. Annals of the Missouri Botanical Garden 26:373-427.
Dumortier, B.C.J. 1829. Analyse des familles des plantes, avec l'indication des principaux genres qui s'y rattachent Tournay: J. Casterman aîné. P. 11. Available at the Biodiversity Heritage Library.
Herbal Information Center. [no date]. Ephedra (Ephedra sinica). Article posted at the URL http://www.kcweb.com/herb/ephedra.htm, accessed 1999.02.21.
Rydin, C., K.R. Pedersen, P.R. Crane and E.M. Friis. 2006. Former diversity of Ephedra (Gnetales): evidence from early Cretaceous seeds from Portugal and North America. Annals of Botany 98(1):123–140.
Stapf, O. 1889. Die Arten der Gattung Ephedra. Denkschr. Kaiserl. Akad. Wiss., Wien. Math.-Naturwiss. Kl. 56(2): 1-112.
Benson, L.D. 1943. Revisions of status of southwestern trees and shrubs. American Journal of Botany 30:230-240.
Carlquist, Sherwin. 1989. Wood and bark anatomy of the New World species of Ephedra. Aliso 12(3):441.
Carlquist, Sherwin. 1992. Wood, bark and pith anatomy of Old World species of Ephedra and summary for the genus. Aliso 13(2):255.
Chaudhri, I.I. 1957. Pakistani Ephedra. Economic Botany 11: 257-262.
Friedman, W. E. 1990. Double fertilization in Ephedra, a nonflowering seed plant: Its bearing on the origin of angiosperms. Science 247:951-954.
Friedman, W. E. 1990. Sexual reproduction in Ephedra nevadensis (Ephedraceae): Further evidence of double fertilization in a nonflowering seed plant. American Journal of Botany 77:1582-1598.
Freitag, H. and M. Maier-Stolte. 1989. The Ephedra-species of P. Forsskal: identity and typification. Taxon 38:545-556.
Freitag, H. and M. Maier-Stolte. 1993. Ephedraceae. In T. G. Tutin (ed.), Flora Europaea, 2nd ed., vol. 1. Cambridge University Press, London, UK.
Freitag, H. and M. Maier-Stolte. 1994. Ephedraceae. In K. Browicz (ed.), Chorology of trees and shrubs in south-west Asia and adjacent regions. Bogucki Publishers, Poznan, Poland.
Hunziker, J.H. 1949. Sinopsis de las species argentinas del genero Ephedra. Lilloa 17: 147-174.
Hunziker, J. H. 1995. The karyotypes of Ephedra ochreata, E. rupestris and E. viridis. Darwiniana 33:369-370.
Ickert-Bond, Stefanie M. 2003. Systematics of New World Ephedra L. (Ephedraceae): Integrating morphological and molecular data. Ph.D. Thesis, Arizona State University, Tempe.
Ickert-Bond, S.M. and M.F. Wojciechowski. 2004. Phylogenetic relationships in Ephedra (Gnetales): evidence from nuclear and chloroplast DNA sequence data. Systematic Botany 29(4):834-849. Abstract: Sequences from the nuclear ribosomal internal transcribed spacer region 1 (nrDNA ITS1) and the plastid rps4 gene from the genus Ephedra (Ephedraceae, Gnetales) were obtained in order to infer phylogenetic relationships, character evolution, and historical biogeography in the genus. Within Ephedra the length of the nrDNA ITS1 varied from 1,081 to 1,143 basepairs (bp), in contrast to dramatically shorter lengths in the outgroups (Gnetum, Welwitschia, and Pinus). The rps4 locus varied in length from 645 to 661 bp in the same set of taxa. Both parsimony and maximum likelihood analyses of these sequences resulted in a well-resolved phylogeny that supports the monophyly of Ephedra, but not its subdivision into the traditional sections Ephedra, Asarca, and Alatae. The resulting phylogeny also indicates a derivation of the New World clade from among the Old World taxa. Among the Old World species three highly-supported monophyletic groups are recognized that are highly concordant with morphological evidence. The New World clade includes two main subclades of North and South American species that are strongly supported, while the position of two, mostly Mexican species E. pedunculata and E. compacta remains unresolved. Character reconstruction of ovulate strobilus types in Ephedra indicates that fleshy bracts are ancestral, with shifts to dry, winged bracts having occurred multiple times. Low levels of sequence divergence within the North American clade suggest either recent and rapid ecological radiation or highly conservative ribosomal DNA evolution within the clade.
Kubitzki, K. 1990. Ephedraceae. In: K. Kubitzki et al., eds. 1990+. The Families and Genera of Vascular Plants. Berlin etc. Vol. 1, pp. 379-382.
Markgraf, F. 1926. Ephedraceae. In: H. G. A. Engler et al., eds. 1924+. Die naturlichen Pflanzenfamilien..., ed. 2. Leipzig and Berlin. Vol. 13, pp. 409-419.
Meyer, C. A. von. 1846. Versuch einer Monographie der Gattung Ephedra. Mem. Acad. Imp. Sci. Saint-Petersbourg, Ser. 6, Sci. Math., Seconde Pt. Sci. Nat. 5(2): 225-298.
Mussayev, I. 1978. On geography and phylogeny of some representatives of the genus Ephedra. Bot. Zurn. (Moscow & Leningrad) 63:523-543. [In Russian.]
Parlatore, F. 1868. Gnetaceae. P.352-359 in A. P. and A. L. P. de Candolle (eds.), 1823-1873. Prodromus Systematis Naturalis Regni Vegetabilis.... Paris etc. Vol. 16, part 2.
Price, Robert A. 1996. Systematics of the Gnetales: A Review of Morphological and Molecular Evidence. International Journal of Plant Sciences 157(6), Supplement: Biology and Evolution of the Gnetales (Nov., 1996), pp. S40-S49.
Rydin, C., K. R. Pedersen, and E. M. Friis. 2004. On the evolutionary history of Ephedra: Cretaceous fossils and extant molecules. Proceedings of the National Academy of Sciences. Available: http://www.pnas.org/cgi/content/full/101/47/16571, accessed 2006.03.21).
Tanaka, Toshihiro; Ohba, Koji; Sakai, Eiji. 1995. Comparison of the Constituents of Ephedra Herbs from Various Countries--On Ephedrine Type Alkaloids. Natural medicines 49(4):418.
Yang, Y., B.-Y. Geng, D. L. Dilcher, Z.-D. Chen, and T. A. Lott. 2005. Morphology and affinities of an Early Cretaceous Ephedra (Ephedraceae) from China. American Journal of Botany 92:231-241.
Zhang J.S., Tian S.Z. and Lou C. 1989. Quality evaluation of twelve species of Chinese Ephedra (Ma Huang). Acta Pharmica Sinica 24: 865-871.
Last Modified 2017-12-29