Thelocactus multicephalus Halda & Panarotto, Acta Mus. Richnov. Sect. natur. 5: 40 (1998).
Descriptio: Species in editione prima operis nostri depicta, T. rinconensi proxima, sed
robusta, caespitosa, multicephala (rarius monocephala) ad 0.7m diametiens et 0.3m alta.
Corpus globosum, 80-200mm latum et 60-150mm longum. pars eius glauca vel
cinerascentia. Tubercula rhomboidea, conica, usque ca 12-25×12-20×10-20mm magna. Spinae
(3-)4(-5), cruciformes, 10-120mm longae. Flores infundibuliformes, autem latiores ad 50mm
diametiens ostendit; perianthii phyla lanceolata, ca 20-30mm longa, integerrima, albida vel
rosea, externa stria media purpurea ornata. Fructus urniformis, ca 10×13mm magnus. Semen
ca 1.5-2.2×1.1-2.1mm magnum; testa tesselata, brunneo-nigra; hilum discoideum.
Holotypus: PR no. JJH8502133 leg. J.J.Halda 14.2.1985.
Patria et Distributio: Mexico septentrio-occidentalis: Nuovo Leon [in vicinitate pagi Sandia
la Victoria ad septentriones versus in declivibus vallis, in fruticetis petrosis ad 800m supra mare.
Plant in many characters similar to T. rinconensis, but very robust, clump-forming,
multiheaded (rarely single) up to 0.7m across and 0.3m tall. Stem globose, 80-200mm across
and 60-150mm tall, with glaucous or cinder-grey epidermis. Tubercles rhomboid, conic, ca 12-25×12-20×10-20mm. Spines mostly 4, reflexed, the lower one up to 140mm long and 0.7-13mm
across. Flowers infundibuliform, ca 50mm across; perianth lobes lanceolate, ca 20-30mm long,
white to pink, the central stripe purple. Fruit urniform, ca 10×13mm large. Seed ca 1.5-2.2×1.1-2.1 mm; testa tesselate, brownish-black; hilum discoid.
An unusual, very robust taxon, creating sometimes clumps up to 65 "heads". One of typical
characters is a simple layer of hypodermatic tissues under the epidermis. This plant is known
among specialists as a "cushion-like, robust T. rinconensis" and its areal is quite large. Recently widely cultivated.
