Thelocactus rinconensis (Poselg.) Britton & Rose

국표에 없다.

Origin and Habitat: It occurs in Coahuila and Nuevo Leon, Mexico.
Altitude: 1200-1900 metres above sea level.
Habitat: It is widespread and quite common in the Chihuahuan Desert in xerophytic shrubland on calcareous soils. There are no major threats to this species, although the habitat is overgrazed by goats.

Common Names include:
SPANISH (Español): Biznaga pezón de la rinconada

Description: Thelocactus rinconensisSN|10887]]SN|10887]] is one of the most decorative cacti of the deserts of Mexico and extremely variable in its spines. Thelocactus rinconensisSN|10887]]SN|10887]] has received many unnecessary infraspecific epithets, and in cultivation it is commonly found under its three varieties, the type and var. nidulans with long spines, var. phymatothele with very short spines, but the only acceptable distinction is Thelocactus rinconensisSN|10887]]SN|10887]] subsp. hintonii, which occurs in Nuevo Leon at some distance from the main population.
Habit: Usually solitary, develops a squat and highly ribbed stem with a flattened top.
Stem: Spherical or somewhat depressed 4-15 cm tall, 9-20 cm across. It can have either a light glaucous-grey or green epidermis sometimes tinged with purple.
Ribs: 20 to 31, rather indistinct, divided into strong tubercles.
Tubercles: Conical, angled quite pointed, elongate toward the tip but flattened on top,12-27 mm long, 7-15 mm wide, 8-15 mm high.
Areoles: Round to elongate, mostly more than 2 cm apart and without nectaries.
Spines: Sometimes absent, very variable in length, depending on the clone, dark, usually black-brown , pale at apex, but also grey, brown or yellow, with a distinctive silvery appearance, and sometimes shredding.
Central spines: 0-4 straight, terete to angled, sometimes scaly with age, variable in length very short or to 6 (or more) cm long.
Radial spines: 0-5 very similar to the centrals, erect to radiating, straight 3-35(-50) mm long.
Flowers: 3-5 cm long, 2,7-3 cm in diameter, salmon-pink or whitish, often yellowish in the throat, or occasionally yellowish or magenta with a dark midvein. Tube short, pericarpels covered
with scales. The plants usually fail to flower until they are 5-9 years old.
Fruit: Spherical ta oblong with scales, 7-9 mm in diameter, greenish or yellowish, slightly fleshy when ripe, opening by basal pore.
Seeds: 1,7-2 mm long, 0,5-1 mm broad, net-patterned with polygonal or square areas.

 

Thelocactus rinconensis (llifle.com)

https://youtu.be/t5DvY0gd4lE?t=204