The rat-tail cactus, Aporocactus flagelliformis, is widely grown and frequently illustrated in beginner’s cactus guides. A. martianus is its uncommon cousin with similar though slightly more robust stems. Both species are included by Barthlott in the genus Disocactus but differ from all others of that genus in their slender, cylindrical, spiny stems. In common to most, however, are the showy, diurnal flowers attractive to hummingbirds. While the flowers of A. flagelliformis are mostly or wholly magenta and strongly zygomorphic, those of A. martianus are red and barely zygomorphic. Both aporocacti are also considerably easier to grow than the generally more finicky, tropical disocacti. Rooted cuts of HBG 72066, collected 20 Jan 1992, by M Kimnach (3220), M Cházaro, R Dorsch & M Negrete, at 7500' elev. in oak-pine woodland, 17 km along the road from the Pan American Highway to Benito Juarez, Oaxaca, Mexico. $5.
Published in the Cactus and Succulent Journal, Vol. 77 (2), March - April, 2005