Astrophytum myriostigma “quadricostatum” var. nudum
Synonyms:
Astrophytum myriostigma cv. quadricostatum nudum
Description:
A. myriostigma “quadricostatum” nudum grows a quadrangular to spherical stem, characterised by the presence of four ribs instead of five. Aging, the plant can get shortly columnar-shaped, getting up to 90 cm tall. The glabrous stem lacks totally or mostly the white flecks typical of this cultivar, showing the bright/blue-green epidermis. After 6 years of live, this Astrophytum may bloom in warm seasons, with pale-yellow, silk-shining flowers arising on the stem top, from the areole.
Cultivation:
This Astrophytum is a quite slow-growing cultivar. It needs a mineral, well-draining substratum, and a good amount of sunlight to grow faster. Water it sparingly from spring to autumn, and during sunny and warm weather you can add a little fertilizer. Theoretically, A. myriostigma quadricostatum is tolerant to freezing temperatures (-7°C), but during winter it needs to be kept perfectly dry to avoid root rot and frost damages.
Propagation:
Even if you can find this Astrophytum grafted on other cacti, usually propagation is done by seeds.
Curiosity:
The original description of this Astrophytum dates back to 1839.