Strombocactus disciformis  is a superb slow-growing miniature plant from Mexico.
The cream blooms are freely produced throughout the summer. The 8 to 10 lobed stigma is white or yellowish.
 

Description: It is a rare geophytes, usually solitary.
Stem: The body is flattened or spherical, 3 to 8 cm high, reaching 20 cm in age, and 3 to 9 cm across. The crown is slightly depressed and felted. The colour is blue-green with greyish tinge, the base covered with brown corky spots in age. It is composed of hard, spirally arranged rhomboid  and imbricate  tubercles, 1 to 1.8 cm high. These tubercules are flattened and almost truncated above and somewhat horny or keeled below.
Spines: 4 to 5, erect and dark grey at the tips and pale grey at the base, 1.2 to 2 cm long, they become calcified, they are caducous and in age fall at the stem base.
Roots: Strong napiform (turnip-like).
Flower: Arise on the crown, measure about 3.5 cm in length and breadth, are shiny cream coloured with occasional spots at the tip and in the throat, The filaments are white or reddish, the anthers yellow. The 8 to 10 lobed stigma are white or yellowish.
Fruit:  7 mm across, splits down its length.
Seeds: Very small.
Blossoming time: flowers emerge early in spring and are freely produced throughout the summer, remaining open for several days.
 

S. disciformis VB143 Villazon, Queretaro Mexico

S. disciformis SB174 Villazon, Queretaro Mexico

Propagation: Seed, At first seedlings are very very small, they take one or two years to reach the diameter of 1 mm!!!  Once they have reached 4 years old or more they are relatively easy to grow - the problem is getting them to 4 years old!

Photo of conspecific taxa, varieties, forms and cultivars of strombocactus disciformis.

• S, disciformis
• S. pulcherrimus ( = S. disciformis ssp. esperanzae)
• S. disciformis forma cristata
• S. disciformis cv. Cactus Art
• S. disciformis forma polytomica

Basionym: Mammillaria disciformis DC., Mem. Mus. Hist. Nat. Paris 17:114 (1828)

Distribution: Mexico ( Quetaro, Hidalgo and Guanajuato )

Habitat: In nearly vertical limestone cliffs and slopes.
 

• Mammillaria disciformis A.P de Candolle 1828.
  Published in:  Mem. Mus. Hist. Nat. Paris 17:114 (1828);
• Echinocactus disciformis (A.P de Candolle) K. Schumann 1894.
  Published in:  Engler and Pranti, Pflanzenfam. 36a:1 89 (1894);
• Ariocarpus disciformis (A.P. de Candolle) W.T. Marshall 1946.
  Published in:  Cact. Succ. J. Amer. 18:56 (1946).
• Echinofossulocactus turbiniformis Lawrence 1841
  Published in:  Loudon, Gard. Mag. 17:318 (1841);
• Echinocactus turbiniformis Pfeiffer 1838
  Published in:  AlIg. Gartenz. 6:275 (1838);
• Mammillaria turbinata Hooker in Curtis 1843
  Published in: Bot. Mag. 69:3984 (1843);
• Cactus disciformis Kuntze 1891
  Published in:  Rev. Gen. P1. 1:260 (1891);
• Cactus turbinatus Kuntze 1891
  Published in:  Rev. Gen. P1. 1:261 (1891);
• Anhalonium turbiniforme Weber in Bois 1893
  Published in:  Dict. Hort. 90 (1893);
• Strombocactus (Turbinicarpus) disciformis (DC.) Backbg.1936
  Published in:  Blat. Kakt. 1 (1936)].

Etymology:  The genus name "Strombocactus" derives from the Greek word “strombos”  meaning ""fir cone, spinning top” treferring to the shape of the plants, and the word “cactus” (an old genus name)
( The genus name implies: "fir cone cactus ").
The species name "disciformis" derives from the Latin adjective “disciformis” which means “disk-shaped, circular, flat,”   ( The specific name implies: "disk shaped")
 

The ripe fruit (about7 mm across) splits down its length releasing the minuscule seeds.