Ephedra (plant)

Ephedra is a genus of gymnosperm shrubs and the only living member of its family, Ephedraceae, and order, Ephedrales. Along with Gnetum and Welwitschia, it is one of three surviving genera in the division Gnetophyta.

As of July 2025, 74 species and two hybrids are recognized. These plants are found in arid regions across southwestern North America, southern Europe, northern Africa, southwest and central Asia, northern China, and western South America. The genus gives its name to the stimulant ephedrine, which it contains in significant amounts.

Description

Most species grow in temperate climates on shores or in sandy soils with full sun. Common English names include joint-pine, jointfir, Mormon-tea, and Brigham tea. In Chinese, they are called mahuang (麻黄), meaning "hemp yellow." The plants are usually shrubs, sometimes climbing vines, and rarely small trees, often spreading via rhizomes.

Their stems are green and photosynthetic. Leaves are opposite or whorled, typically scale-like and fused into a sheath at the base, often shed early; they lack resin canals. Most species have rudimentary, non-photosynthetic leaves, though a few, such as E. altissima, develop slender, leaf-like leaves up to 5 cm long. Ephedra species are mostly dioecious.

Male strobili occur in whorls of 1–10 with decussate bracts, and the pollen is furrowed. Female strobili also grow in whorls, with bracts that fuse around a single ovule; these bracts may be white or red. Each strobilus usually produces 1–2 yellow to dark brown seeds.

The genus Ephedra was first described by Carl Linnaeus in 1753, with E. distachya as the type species. The family Ephedraceae was named by Barthélemy Charles Joseph Dumortier in 1829. The oldest known fossils of the genus date to the Early Cretaceous, about 125 million years ago, with records from Argentina, China, Portugal, and the United States.

Evolutionary history

After the Early Cretaceous, fossil evidence of Ephedra beyond pollen disappears. Molecular clock estimates suggest the last common ancestor of living species lived during the Early Oligocene, around 30 million years ago. However, pollen with branched pseudosulci—a trait that evolved independently in modern North American and Asian lineages—is known from the Late Cretaceous, indicating the common ancestor is at least that old.