Ephedraceae

Common Names

Mormon-tea or joint-fir family (Stevenson 1993), [Chinese].

Taxonomic notes

Includes one genus, Ephedra, which see. Many authors designate this the sole family in Order Ephedrales. 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.

Description

Dioecious (very rarely monoecious), erect or climbing shrubs or vines. Bark grey to reddish brown, cracked and fissured, often fibrous. Branches numerous, round, whorled to fascicled, finely longitudinally grooved, internodes 1-10 cm. Roots generally fibrous. Leaves mostly not photosynthetic; simple, scalelike, opposite and decussate or whorled, connate at base to form 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).

Range

Warm temperate America, Asia and Europe (Ali and Qaiser 1987). Most species are found in semiarid habitats.

Big Tree

Oldest

Dendrochronology

No record of use for any species.

Ethnobotany

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 (e.g., over 7000 Web pages!) 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]).

Observations

Remarks

For proper identification of Ephedra, fruiting and flowering material is essential. Many sterile specimens of various taxa look alike (Ali and Qaiser 1987).

Citations

Herbal Information Center. [no date]. Ephedra (Ephedra sinica). Article posted at the URL http://www.kcweb.com/herb/ephedra.htm, accessed 21-Feb-1999.

Huang, J., D. E. Giannasi and R. A. Price. 2005. Phylogenetic relationships in Ephedra (Ephedraceae) inferred from chloroplast and nuclear DNA sequences. Molecular Phylogenetics and Evolution 35(1):48-59. Abstract: Sequences of the nuclear ribosomal DNA internal transcribed spacer region 1 and the chloroplast-encoded genes maturase K and ribulose-1,5 biphosphate carboxylase large subunit were obtained from species of Ephedra (Ephedraceae) representing the geographic range and morphological diversity of the genus. Phylogenetic analyses of the DNA data indicate that relationships within the genus are better predicted by geographic region of origin than by ovulate cone characters. The sampled species with dry, winged (versus fleshy) ovulate cone bracts or single-seeded cones do not form monophyletic groups and therefore the previous classification systems of Ephedra based on these aspects of bract morphology appear to be largely unnatural. Three groups were identified among the Old World species studied, one comprising European and Mediterranean species and two including only Asian species. The sequence data suggest a possible early divergence of a New World clade of Ephedra from among the Old World groups. The South American species form a distinct clade apparently related to one of two groups of North American species, which accords with a frequent floristic pattern of close relationships between species groups in western South America and southwestern North America.

See Also

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.

Caveney, S., D. A. Charlet, H. Freitag, M. Maier-Stolte, and A. N. Starratt. 2001. New observations on the secondary chemistry of world Ephedra (Ephedraceae). American Journal of Botany 88:1199-1208.

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.

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. (Ephedraceeae): 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 nat�rlichen Pflanzenfamilien..., ed. 2. Leipzig and Berlin. Vol. 13, pp. 409-419.

Meyer, C. A. von. 1846. Versuch einer Monographie der Gattung Ephedra. M�m. Acad. Imp. Sci. Saint-P�tersbourg, S�r. 6, Sci. Math., Seconde Pt. Sci. Nat. 5(2): 225-298.

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.

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).

Stapf, O. 1889. Die Arten der Gattung Ephedra. Denkschr. Kaiserl. Akad. Wiss., Wien. Math.-Naturwiss. Kl. 56(2): 1-112.

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.