Astrophytum myriostigma “tricostatum” var. nudum
Astrophytum myriostigma tricostatum nudum
A. myriostigma tricostatum is characterised by the presence of only three ribs on its stem. Sometimes, the plant will develop more ribs while aging. The glabrous stem lacks totally or mostly the white flecks typical of this cultivar, showing the bright-green/blue-green to rey-green epidermis. After 6 years of life, during warm season this plant will bloom from spring to early summer, with large, yellow flowers arising from the areole at the tip of the stem.
This Astrophytum is a quite slow-growing cultivar. It needs a mineral, well-draining substratum, and a good amount of sunlight to grow healthy: its appearance will get more beautiful when it is grown in light shade. Water sparingly from spring to autumn, and during the warm season you can add a little nitrogen fertilizer. Theoretically, this plant is tolerant to freezing temperatures (-7°C/-10°C ), but in winter it has to be ketp perfectly dry to prevent root rot and frost-damages.
Propagation is usually done by seeds, but sometimes this Astrophytum is grafted on other cacti.
Old and big three-ribbed Astrophytum are beautiful, rare and in consequence, high-prized.