Ephedraceae Dumort.

Shrubs or vines , erect or clambering, Equisetum-like, dioecious (very rarely monoecious). Bark gray to reddish brown, cracked and fissured. Branches generally many, terete, whorled to fascicled, finely longitudinally grooved, internodes 1--10 cm. Roots generally fibrous. Leaves simple, opposite and decussate or whorled, scalelike, connate at base to form sheath, generally ephemeral, mostly not photosynthetic; resin canals absent. Pollen cones compound, 1--10 in whorls at nodes; each compound cone composed of 2--8 sets of opposite or whorled membranous bracts, proximal bracts empty, each distal bract 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 compound, 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; cotyledons 2.