Astrophytum Quadricostatum Nudum Description: Astrophytum myriostigma var. nudum (nude form also known as “Hekiran” in Japanese speech) 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.
It is by some considered an extreme form of the subspecies potosinus.
Stem: Spherical to shortly columnar with age. The stems is smooth and can be over 120 cm tall and 5-10 cm in diameter and are shaped like a bishop’s headpiece or a star.
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
Astrophytum Quadricostatum Nudum Cultivation and Propagation: Astrophytum myriostigma is a summer grower species relatively easy to grow. It is sometime seen as a grafted plant but grows very well on its own roots too.
Growth rate: It is a slow growing and easily flowering species.
Soil: Use mineral well permeable substratum with little organic matter (peat, humus), plants may become too elongated if compost is too rich.
Repotting: Re-pot every 2 years. Use pot with good drainage.
Astrophytum Quadricostatum Nudum Fertilization: It grows much faster with a low nitrogen content fertilizer in spring and summer. Potassium helps maintaining the plants compact and healthy.