Thelocactus hastifer

T. hastifer (Werdermann & Bödeker) F. Knuth in Backeberg & Knuth, kaktus-ABC 360 (1935); Werdermann & Bödeker, Notizbl. Bot. Gart. u. Mus. Berlin-Dahlem, 11:104, 274-6 (1930-34) - as Echinocactus hastifer; Backeberg, Die Cact. 5:2811 (1961); E.F. Anderson, Bradleya 5: 58, 66 (1987); E.F. Anderson, S.A. Montes & N.P. Taylor, Threatened Cacti of Mexico 89 (1994); Alsemgeest, Bregman & van Veldhuisen, Succulenta 74(3): 125-129 (1995)

This is one of the rarest species of the genus, occurring at about the southernmost limit of the genus, in Querétaro, where I was taken to see it in 1994 in the wild by Manuel Rivas, a Mexican gentleman of Scottish descent.

It is described as usually single, clustering only after many years, from the base. In cultivation it was 15 years or more before specimens I grew from seed produced offsets. It has long, cylindrical stems, distinctly very narrow at the base, 10 to 30cm or more tall, often collapsing, or rather reclining, under its own weight, and sometimes seen in the wild coming horizontally out of cracks in large rocks, the growing point straining to keep upright.

There are 12 to 18 narrow ribs, vertical or spiralling slightly. Areoles sometimes with or sometimes without extrafloral nectaries. Central spines 4 or 5, straight, needle-like, with one, dominant, very long spine; 10 to 14mm, the longer spine to 26mm, white to yellowish-brown, the centre spine becoming dark brown with age and erect, the others radiating slightly. Radial spines 20 to 25, 12 to 15mm long, white, darker as they age, straight, radiating. Flowers are pinkish-magenta, with paler throat, 3.5 to 5cm wide, 2.5 to 3cm long; filaments white, anthers yellow, style whitish-magenta, stigma lobes 5 to 7, yellow.

Reported to be very localized in the state of Querétaro between Cadereyta and Vista Hermosa (a small village at the edge of the barranca of the Rio Moctezuma), at 1800 to 2000m altitude, from 20°30' to 21°N, and from 99°30' to 99°45' W.

Because of its very restricted occurrence it is considered an endangered species, but its remote occurrence makes it less likely to be under threat from collectors.

(Left) T. hastifer, in cultivation, a plant collected originally from habitat (Right) T. hastifer, in cultivation, cutting from an old collected plant from the 1930's