15. Bergerocactus Britton & Rose, Contr. U.S. Natl. Herb. 12: 435. 1909.
Snakecactus [for Alwin Berger, 1871-1931, German cactologist and horticulturist at La Mortola, Italy, and Cactus, an old genus name]
Arthur C. Gibson
Shrubs, ascending to erect, spreading, or reclining, usually much branched near base, forming thickets. Roots diffuse. Stems somewhat segmented, green, long cylindric, 30-150 × 3-5(-6) cm, glabrous; ribs (12-)14-18, rounded; tubercles low, indistinct; areoles to 10 mm apart on rib crests, circular, felty; areolar glands absent; cortex and pith mucilaginous. Spines 30-45 per areole, straw colored, aging brown, acicular, terete; radial spines 6-13 mm; central spines 1-3 per areole, to 60 mm, longest spines bend downward. Flowers diurnal, lateral to terminal on stems, from adaxial edge of areole, never on first-year shoots, funnelform, 3.5-5 cm; flower tube 15-20 mm; tepals 12-20 mm; outer tepals yellow with green or reddish midstripes and tips, oblanceolate; inner tepals yellow, oblanceolate to oblong; ovary subglobose, spines usually absent; scales deltate to ovate or awl-shaped, 1-4 mm, margins entire, with tannish hairs in axils, spiny or spineless; stigma lobes 9-11, pale yellow, 4-5 mm. Fruits dehiscent by extruding ribbon of pulp with seeds through apical pore, green with reddish tubercles, spheric, 25-30 mm, juicy, becoming dry after dehiscence, densely spiny like stems; pulp red; floral remnant persistent. Seeds black, obovoid, 2-3 mm, glossy; testa cells ± flat to slightly concave. x = 11.
Species 1: sw United States, nw Mexico.
SELECTED REFERENCES
Moran, R. V. 1965. Revisión de Bergerocactus. Cact. Suc. Mex. 10: 51-59. Moran, R. V. 1966. The fruit of Bergerocactus. Natl. Cact. Succ. J. 21: 30-31.
