Astrophytum myriostigma tricostatum
Description: Astrophytum myriostigma var. tricostatum is a strikingly pretty, old cultivar with only three ribs with light or dense white flecks that cover the stem. Nude plants (see) are also known and very appreciated. This cultivar tends to be unstable, and some of the three ribbed specimens develop additional ribs as they age. Old and big plants which maintain the typical three ribbed shape are very very prized.
Flowers: arise from the areole at the tip of the stem on mature plant (at least 4-5 years old) they are large, funnel-shaped, yellow, 5-7 cm wide. Blooming intermittently throughout the warm months from spring to autumn.