Description
Astrophytum myriostigma var. nudum (nude form) is very similar to the other myriostigma, it only deviate from the well-known typical form for lacking or mostly lacking white flecks, giving a bright green, blue-green, gray-green or mauve-green color overall depending on clones.
Coloured form: The schizochromic form Astrophytum myriostigma var. nudum f. colorata has yellow, orange or red stems due to the absence (or reduced production) of chlorophyll pigments: every other pigment is present at normal levels, the dominant green colouration is lost, but will still more than likely have normal other pigments that give the yellow overall appearance of the stem. The cololured forms are very attractive and highly prized. Thise schizochromic forms are almost always seen grafted on stronger columnar species, and cannot can be grown on their own roots. However some clones have enough chlorophyll in their tissues and can be grown on they own roots too, but very slow growing.
Stem: Spherical to shortly columnar with age. The stems is smooth and can be over 20 cm tall and 5-10 cm in diameter and are shaped like a bishop’s headpiece or a star.
Spines: None.
Ribs: The number of ribs vary from 3 to 8 (usually 5).
Flowers: 5 cm in length, pale-yellow, silk-shining unlike the white-spotted plant, occasionally with an orange gloom.
Blooming season: Spring or early summer, They take up to 6 years to bloom.
Fruits: Dry, dehisces towards the apex forming about 5 star shaped lobes. With few seeds.
Origin and Habitat
Garden origin (Nursery produced cultivar)
Cultivation and Propagation
Variegated and albinous cacti are regarded as choice and difficult in cultivation, but despite that many of them are relatively easy to grow. But be aware that they cannot tolerate prolonged exposure to direct sun light (especially during the hottest summer days), so grow them in half-shade or under filtered sun. They are sometime seen as grafted plants, but many grow well on their own roots, too.
On the contrary, the albinos can survive only if grafted on a strong green base.
Use mineral well-permeable substratum with little organic matter (peat, humus). Water sparingly from March till October and keep perfectly dry in winter at temperatures from 5 to 15 degrees centigrade. (In general these plants are more tender and cannot endure freezing temperatures ) In the rest period no high atmospheric humidity!!
Propagation: Usually by seed. Plants are often grafted onto column-shaped cacti.