Acharagma roseana

Acharagma roseana (Boedeker) E.F. Anderson, Cact. Succ. J. (Los Angeles) 71: 323, 1999. Echinocactus roseanus Boedeker, Z. Sukkulentenk. 3: 363, fig. 1928. Neolloydia roseana (Boed.) F.M. Knuth in Backeb. & F.M. Knuth, Kaktus-ABC p. 368, 1935. Thelocactus roseanus (Boed.) Borg, Cacti (Borg) p. 282, 1937. Escobaria roseana (Boed.) Buxb., Oesterr. Bot. Z. 98: 79, 1951. Gymnocactus roseanus (Boed.) Glass & Foster. Cact. Succ. J. (Los Angeles) 42: 234, 1970. Type: H. Ritter s.n., sandstone, near Saltillo, Coahuila, Mexico; holotype: N/A. It is not clear if a specimen was deposited in an herbarium. Boedecker states, “diese sehr hübsche Pflanze wurde ebenfalls von Herrn Ritter (Saltillo) gesammelt und mir zugeschickt.”

 

Plants usually solitary, rarely branching basally, forming small cespitose clumps. Stems globose to cylindroid when mature, bright green, 4-6 cm high, 1.5-5 cm in diameter. Tubercles arranged in rows (3/5, 5/8 or 8/13 spirals), 3-5 mm in basal diameter, protruding 3-4 mm. Central spines 4-6, similar to radials but somewhat curved, pale yellow to bright golden yellow, 5-20 mm long. Radial spines 15-30, yellowish to brownish, 8-15 mm long. Flowers pink with dark reddish-pink midveins or cream colored, 15-20 mm long and in diameter. Fruit green, often tinged with pink, 10-15 mm long. Endemic to southeastern Coahuila (north and west of Saltillo), adjacent and central Nuevo Leon, Mexico; on sandstone or igneous substrates; 1500-2300 m elevation.

Two subspecies are currently recognized; however, Zimmerman (in Henrickson & Johnston 1998) suggests that there are three different races, representing the three disjunct occurrences of Acharagma roseana.

1. Stems globose, 4-5 cm tall, ca. 4 cm in diameter; radial spines ca. 15; flowers to 20 mm long, pink. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .subsp. roseana

1’. Stems cylindroid, 5-6 cm tall, ca. 1.5 cm in diameter; radial spines ca. 30; flowers to 15 mm long, cream with a pink midrib. . . . . . . . . . . . . . . . . . . subsp. galeanensis

 

Acharagma roseana (Boedeker) E.F. Anderson subspp. galeanense (Haugg) D.R. Hunt, Cactaceae Syst. Init. 14: 7, 2002. Escobaria roseana (Boed.) Buxb. subsp. galeanensis E.Haugg, Kakteen Sukk. 46: 76 (fig.), 1995 . Type: E. Haugg 3134, near Galeana, in gypsum-rich soil, Nuevo León, Mexico, 1978; holotype: MEXU, isotype: WU.