Thelocactus rinconensis SB301 Rinconada, Nuevo Leon, Mexico.
The remarkable characteristics of this species are a depressed and glaucous body and very long spines, SB301 Rinconada.
 

Description: Usually solitary, develops a squat and highly ribbed stem with a  flattened top, up to 20 cm in diameter.  It can have either a glaucous-grey or green epidermis,
Spines: Variable in length, depending on the clone, dark, usually black-brown but also grey or yellow, with a distinctive silvery appearance, and sometimes shredding.
Flowers: pink or whitish, the plants usually fail to flower until they are 5-9 years old.

Cultivation: Easy to cultivate. Water moderately from Spring to Autumn. In Winter, keep dry.
Sun Exposure: Full sun to light shade.

Reproduction: Nearly always from seed, since the plant rarely produces plantlets.

Photo of conspecific taxa, varieties, forms and cultivars of Thelocactus rinconensis:

• T. rinconensis

• T. rinconensis ssp. freudenbergeri

• Thelocactus rinconensis var. phymatothelos

Origin: occurs Coahuila and Nuevo Leon, Mexico.

Synonyms:

• Thelocactus lophothele var. nidulans
• Echinocactus nidulans
• Thelocactus rinconensis var. phymatothelos
• Echinocactus phymatothelos
• Thelocactus rinconensis var. nidulans
• Thelocactus rinconensis ssp. phymatothelos
• Thelocactus nidulans,
• Thelocactus phymatothelos Poselger ex Ruempler,
  in Förster, Handb. Cact., ed. 2, 602 (1885)
• Thelocactus phymatothelos Br. & R. (' phymatothele'),
  Cact. 4: 8 (1923)
• Thelocactus multicephalus
• Thelocactus lophothele Br. & R.,
  Bull. Torrey Bot. Club 49: 251 (1922)
• Echinocactus lophothele Salm-Dyck,
  Allg. Gartenz. 18: 395 (1850).
• Thelocactus rinconensis ssp. freudenbergeri
• Thelocactus rinconensis var. freudenbergeri
• Echinocactus rinconensis Poselger,
  Allg. Gartenz. 23: 18 (1855).
• Echinocactus rinconadensis Schumann,
  Gesambt. Kakt. 433 (1898).
• Thelocactus rinconensis ssp. multicephalus
• Thelocactus rinconensis ssp. nidulans

Thelocactus rinconensis

Thelocactus rinconensis var. phymatothelos Glass & Foster, Cact. Succ. J. (US) 49: 246 (1977). Thelocactus rinconensis ssp. phymatothele (Poselger) Glass, Ident. Guide Threatened Cacti of Mexico 1: TH/RIN (1997). Thelocactus rinconensis ssp. phymatothelos (Poselger) Doweld nom. superfl., Sukkulenty 1: 30 (1999). Thelocactus rinconensis ssp. icamolensis Halda & Kupcak, Acta Mus. Richnov. Sect. natur. 7: 75 (2000).

T. lophothele (rinconensis).