A. myriostigma  var. strongylogonum (a Japanese selected specimen)
This variety has a wavy and corrugated surface and shows alternating furrows down the body, the ribs are fat and rounded.

This variety is very popular among Japanese cactus fanciers, which selected beautiful plants with enhanced “strogylogonum” trait.
 

Description: Astrophytum myryostigma var. strogylogonum  differs from the other typical myriostigmas for the 5 fat ribs that are always rounded and noticeably curved. With age horizontal furrows will mark the sides of the ribs as well the midline line between the edges of two contiguous ribs is characteristically ondulated.
The stems is also usually darker green, strong, compact and flat.
The flowers are larger and purely yellow.

There is also a pure green form (lacking the white hairy scales) that has been classified as:
Astrophytum myriostigma var. strongylogonum  subvar. nudum (Rob.Mey.) Backeb.

Cultivation: It is relatively easy to grow. Use mineral well permeable substratum (rot prone). Water sparingly from March till October and keep perfectly dry in winter at temperatures from 5 to 15 degrees centigrade. (but it is Hardy to -5°C for short periods) In the rest period no high atmospheric humidity!! Sun Exposure: Light shade to full sun.

Propagation: They can be propagated from seed.

Photo of conspecific taxa, varieties, forms and cultivars of Astrophytum myriostigma:

• A. myriostigma
• A. myriostigma bicostatum
• A. myriostigma columnare
• A. myriostigma cv. FUKURYU
• A. myriostigma cv. HAKUUN
• A. myriostigma cv. HAKUUN nudum
• A. myriostigma cv. HAKUUN nudum forma cristata
• A. myriostigma cv. HUBOKI
• A. myriostigma cv. HUBUKI
• A. myriostigma cv. KIKKO
• A. myriostigma cv. LAIMAKE
• A. myriostigma cv. LOTUSLAND
• A. myriostigma maculatus forma cristata
• A. myriostigma multicostatum
• A. myriostigma nudum
• A. myriostigma nudum cv MAIDEN BLUSH
• A. myriostigma nudum variegata
• A. myriostigma cv. ONZUKA
• A. myriostigma cv. ONZUKA ball type
• A. myriostigma cv. ONZUKA columnare
• A. myriostigma cv. ONZUKA cristata
• A. myriostigma cv. ONZUKA + HAKUUN
• A. myriostigma cv. ONZUKA quadricostatum
• A. myriostigma cv. ONZUKA tricostatum
• A. myriostigma cv. ONZUKA tricostatum FUKURYU
• A. myriostigma cv. ONZUKA white form
• A. myriostigma quadricostatum
• A. myriostigma quadricostatum nudum
• A.myryostigma v. strongylogonum
• A. myriostigma v. strongylogonum cv. COSTA
• A. myriostigma tricostatum
• A. myriostigma tricostatum FUKURYU type1
• A. myriostigma tricostatum nudum
• A. myriostigma variegatum

Scientific name:  Astrophytum myriostigma var. strongylogonum Backeberg

Original description: (but nowadays regarded as not valid): Die Cactaceae Gustav Fischer Verlag, pag: 2661 (1960)

Type locality:  Mexico, San Luis Potosi (Villar), in the East part of the state
(It  was found  growing along with Turbinicarpus knuthianus and Mammillaria aureilanata)

Origin: Border of San Luis Potosi and Tamaulipas, in the Tampico area.

Conservation status: Listed in CITES appendix 2.

A young 6 years old seedling
(Original Japanese seeds from Kotokudo cactus nursery)

A four ribbed specimen