EPHEDRACEAE

Ephedra is a genus of gymnosperm shrubs, the only genus in its family, Ephedraceae, and order, Ephedrales. The various species of Ephedra are widespread in many lands, native to southwestern North America, southern Europe, northern Africa, southwest and central Asia, northern China, and western South America.

In temperate climates, most Ephedra species grow on shores or in sandy soils with direct sun exposure. Common names in English include joint-pine, jointfir, Mormon-tea, or Brigham tea.  Ephedra is also sometimes called sea grape (from the French raisin de mer), a common name for the flowering plant Coccoloba uvifera.

The family, Ephedraceae Dumort., of which Ephedra is the only genus, are gymnosperms, and generally shrubs, sometimes clambering vines, and rarely, small trees. Members of the genus frequently spread by the use of rhizomes.

The stems are green and photosynthetic. The leaves are opposite or whorled. The scalelike leaves fuse into a sheath at the base and this often sheds soon after development. There are no resin canals.

The plants are mostly dioecious: with the pollen strobili in whorls of 1-10, each consisting of a series of decussate[6] bracts. The pollen is furrowed. The female strobili also occur in whorls, with bracts which fuse around a single ovule. There are generally 1-2 yellow to dark brown seeds per strobilus.

Ephedraceae are adapted to extremely arid regions, growing often in high sunny habitats, and occur as high as 4000 m above sea level in both the Andes and the Himalayas.

Plants of the genus Ephedra, including E. sinica and others, have traditionally been used by indigenous people for a variety of medicinal purposes, including treatment of asthma, hay fever, and the common cold. The alkaloids ephedrine and pseudoephedrine are active constituents of E. sinica and other members of the genus. These compounds are sympathomimetics with stimulant and decongestant qualities and are chemically substituted amphetamines.

Alkaloids obtained from the species of Ephedra used in herbal medicines, which are used to synthetically prepare pseudoephedrine and ephedrine, can cause cardiovascular events. These events have been associated with arrhythmias, palpitations, tachycardia, and myocardial infarction. Caffeine consumption in combination with ephedrine has been reported to increase the risk of these cardiovascular events.