A Revision of Ariocarpus (Cactaceae). I. The Status of the Proposed Genus Roseocactus

Abstract

Anderson, Edward F. (Claremont Graduate School, Claremont, California.) A revision of Ariocarpus (Cactaceae). I. The status of the proposed genus Roseocactus. Amer. Jour. Bot. 47(7) : 582–589. Illus. 1960.—The proposed genus Roseocactus Berger is found to be a subgenus of Ariocarpus. The subgenera Ariocarpus and Roseocactus are basically similar in habitat, seedlings, presence of mucilage systems, tubercle structure, seed structure, fruiting habit, flower origin and structure, alkaloidal properties, trichomes, pollen grains, and chromosome number. They differ in flower color, presence or absence of an areolar groove, tubercle divergence, and trichome texture. A hypothesis is proposed to explain variations in the areoles. The differences in structure of mature tubercles are thought to be due to variability in the location of growth and elongation with respect to the floral and spinous areolar areas.

A Revision of Ariocarpus (Cactaceae). II. The Status of the Proposed Genus Neogomesia

“…14). This is in contrast to the highly dimorphic condition of the areoles of A. retusus reported earlier (Norman H. Boke, personal correspondence; Anderson, 1960). Measurements of the distance of the areolar region from the tubercle tip in relation to the total tubercle length show little change in the distance between areole and tip in young and fully mature tubercles (Fig.…”

“…None of the species of Ariocarpus have crystalline material except in the mucilage. Areoles-Earlier studies (Anderson, 1960) showed that although there is some variation of areolar structure, all flowers are borne from areolar regions at the bases of the tubercles (Fig. 11).…”

“…However, Buxbaum (1950), Meyran (1956), and Anderson (1960) have studied the seedlings of other species of Ariocarpus.…”

A Revision of Ariocarpus (Cactaceae). IV. Formal Taxonomy of the Subgenus ariocarpus

“…THE FIRST 2 articles of this series (Anderson, 1960(Anderson, , 1962 delimited the characters of Ariocarpus and showed that 2 previously segregated genera, Roseocactus and Neogornesia, have numerous characters in common with Ariocarpus and should be included within the genus. The third article (Anderson, 1963) colntained an introduction to the formal taxonomy of the genus with sections on geographical distribution and habitat, policy of classification, herbaria consulted, and acknowledgments.…”

A Revision of Ariocarpus (Cactaceae). III. Formal Taxonomy of the Subgenus Roseocactus

“…THE PREVIOUS 2 articles of this series (Anderson, 1960(Anderson, , 1962 delimited the characters of Ariocarpus and showed that the previously segregated genera Roseocactus and Neogornesia have numerous characters in common with Ariocarpus. The latter species consists of 2 varieties, var.…”