(This plant comes in a 3.5" pot. You will receive a very similar plant to the one in the picture. It may or may not be blooming at the time of your purchase. The plant is shipped in its pot to prevent any damage to the roots).
This solitary and cylindrical form cactus is a rugged plant resistant to root rot and easy to grow in a well-drained soil. It is dark green when grown in filtered light or shade. It develops numerous white woolly flakes for protection from the sun. It flowers throughout the summer, flowers are about 2.5" long in canary yellow color
Recommended temperature zone: USDA: 9b-10
Frost tolerance: Hardy to 20° F (-6°C)
Sun exposure: Light shade
Origin: Mexico (Querétaro, Hidalgo)
Growth habits: Solitary columnar cactus, up to 4" tall (1.2 m), 6 inches in diameter (15 cm); usually 8 ribs; 1 central spine; 5 to 10 radials
Watering needs: Moderate water in summer. Allow the soil to dry before watering again. Do not water in winter.
Propagation: Seeds that germinate rapidly.
Blooming habits: The Astrophytum ornatum blooms in summer. The 2.5" wide flowers (6 cm) are pale yellow and scented. It needs to be 6" tall to bloom (15 cm). This might take six years or more depending on the length of its growing period in your local conditions.
Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz