The Gymnosperm Database


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Conservation status

Ephedra antisyphilitica

Berlandier ex Meyer 1846

Common names

Clap-weed, popote, tepopote, Cañatilla (Torrey 1858, Stevenson 1993).

Taxonomic notes

Syn: Ephedra antisyphilitica var. brachycarpa Cory; E. occidentalis Torrey ex Parlatore; E. texana Reed (Stevenson 1993).


"Shrubs erect or spreading, 0.25-1 m. Bark gray, slightly cracked and irregularly fissured. Branches alternate or whorled, rigid, angle of divergence about 45°. Twigs green, becoming yellow-green with age, glaucous, not viscid, with numerous longitudinal grooves; internodes 2-5 cm. Terminal buds conic, 1-3 mm, apex obtuse. Leaves opposite, 1-3 mm, connate to 2/3-7/8 their length; bases thickened, brown, completely deciduous; apex obtuse. Pollen cones 1-2 at node, lance-ellipsoid, 5-8 mm, sessile to nearly sessile; bracts opposite, 5-8 pairs, pale green to red, obovate, 2-4 × 2-3 mm, membranous, connate at base; bracteoles slightly exceeding bracts; sporangiophores 4-5 mm, 1/2 exserted, with 4-6 sessile to very short-stalked (less than 1 mm) microsporangia. Seed cones 1-2 at node, ellipsoid, 6-12 mm, sessile to nearly sessile; bracts opposite, 4-6 pairs, ovate, 5-7 × 5-10 mm, connate to 1/8-7/8 their length, inner pairs becoming fleshy and red. Seeds 1(-2), ellipsoid, 6-9 × 2-4 mm, light brown to chestnut, smooth. ... Coning March-April" (Stevenson 1993).

Distribution and Ecology

US: Oklahoma and Texas; Mexico: Nuevo León and San Luis Potosí; at 100-1200 m on dry soils and rocky slopes. "Mexican populations ... are disjunct from those in Texas." (Stevenson 1993).

Big tree



Torrey (1858) says "the Mexicans ... use a decoction of it as a remedy for gonorrhea."




Torrey, J. 1858. Botany of the boundary. In W.H. Emory, Report on the United States and Mexican Boundary Survey, Vol. 2, Part 2. Washington, D.C.: A.O.P. Nicholson. Available at, accessed 2009.02.13.

See also

Last Modified 2017-12-29