Notocactus uebelmannianus Buining

Description: Parodia werneri is a a nice cactus usually solitary, sometimes branching basally to form small clumps. It has glossy green body with appressed spines and bears a ring of the most amazing magenta to royal purple flowers every spring.
Replaced synonym: Notocactus uebelmannianus Buining, Kakt. and. Sukk. 19(9): 175-176 (1968), non Parodia uebelrnannlana Ritter, Kakt. Siidamer. 2: 425-426 (1980). On transfer to Parodia since a Parodia uebelmanniana already existed the name of uebelmannianus was changed to Parodia werneri, hence the name Parodia werneri is the current accepted Scientific name but many growers and plant sellers still use the old name Notocactus uebelmannianus, so you may come across it under both names.
Stem: Shiny dark green, globular or short/squatty up to 12 cm tall and 17 cm in diameter.
Ribs: 12-16, flat, round, more ore less chinlike.
Areoles: Round, large, dull white or creamy white-felted, each with a shallow groove below.
Central spines: Usually absent.
Radial spines: About 6 spider-like, 10 to 30 mm long, appressed against the stem body, one pointing downward, unequal, white to greyish.
Flower: Small about 5 cm in diameter, short funnel-form, shiny, wine red to deep magenta of various tones, or pure yellow (Parodia werneri f. flaviflora). Both purple and yellow flower colours can exist side by side in some populations and the yellow being the most abundant. Therefore the more commercial but less representative purple flowered form was made the species and the more typical yellow flowered the variety.
Blooming season: Spring to early summer, once it reaches about 7 cm in diameter if kept well it will flower every year.

www.llifle.com/Encyclopedia/CACTI/Family/Cactaceae/19998/Notocactus_uebelmannianus