Astrophytum myriostigma var. columnare, known commonly as the Columnar Bishop’s Cap, is a stunning and unique cactus species native to the high deserts of northeastern Mexico. This rare variety of the more widely known Astrophytum myriostigma is distinguished by its taller, columnar form, making it an exceptional choice for collectors, architectural desert gardens, and succulent enthusiasts seeking something truly out of the ordinary.

Whereas the standard myriostigma tends to remain globular or squat in shape, the columnare variety elongates gracefully, forming upright, cylindrical stems that can reach 18 to 24 inches tall over time. The surface of the cactus is marked by 5 to 7 pronounced ribs, creating a star-shaped cross-section that gives the plant its common name: Bishop’s Cap. The stems are generally light green to gray-green in color and are often dusted with tiny, white trichomes that form a dotted or “flecked” pattern. These trichomes reflect sunlight, helping the plant tolerate intense exposure in its native habitat.

One of the most attractive qualities of Astrophytum myriostigma var. columnare is its spineless surface, giving it a clean, geometric look that contrasts beautifully with spiny companion cacti or rough-textured rock. This lack of spines makes it safer to handle and ideal for close planting in container arrangements, windowsill gardens, or modern desert landscapes.

During the growing season, this cactus may produce bright yellow flowers at the crown of the stem, particularly in late spring and summer. The flowers are typically 2 to 3 inches across and may have a faint citrus-like fragrance. In ideal conditions, mature plants can flower more than once per year, adding a soft yet vibrant element to its sculptural form. After flowering, the plant may form small, woolly fruits that contain seeds for future propagation.

From seed, Astrophytum myriostigma var. columnare can be grown successfully with patience and proper care. Seeds usually germinate within 1 to 3 weeks when kept warm and moist, ideally in a bright but indirect light setting. While slow-growing, seedlings begin to take on their iconic ribbed shape fairly early. As they mature, their columnar habit becomes more pronounced, eventually forming upright stems that stand tall among other succulents and cacti.

This cactus is well suited to dry, rocky soils with excellent drainage. It prefers full sun in cooler climates, but some afternoon shade may be necessary in extremely hot environments to prevent sun scorch. Watering should be infrequent—typically only when the soil has dried completely—and winter watering should be minimal to prevent root rot.

**Why Grow Astrophytum myriostigma var. columnare from Seed?**

Unique, upright growth habit different from the standard Bishop’s Cap
Clean, spineless surface with attractive white flecking
Ideal for architectural or minimalist garden designs
Bright yellow flowers add seasonal interest
Slow-growing and long-lived, perfect for collectors and specialty growers
Rare in cultivation, especially from seed
Well adapted to containers, rock gardens, or high desert landscapes
Grows into a stately specimen over time with little maintenance

Growing Conditions

Light: Bright indirect light to full sun
Soil: Gritty, fast-draining cactus mix or sandy loam
Water: Water deeply but infrequently; allow soil to dry completely between waterings
Temperature: Hardy to about 20°F (-6°C) in dry conditions
Fertilizer: Use a low-nitrogen cactus fertilizer during the active growing season (spring and summer)
Propagation: Best grown from seed; grafting is sometimes used to accelerate growth

Whether displayed as a living sculpture on a patio or cultivated in a collector’s greenhouse, Astrophytum myriostigma var. columnare is a remarkable plant that embodies both resilience and elegance. Its rare form, easy care, and spineless beauty make it a sought-after gem among cactus lovers and landscape designers alike. Grow it from seed and watch as it transforms over time into a tall, architectural masterpiece of the desert world.