Notocactus rudibuenekeri albissimo

This unique and beautiful fuzzy cactus has long and very white and soft spines. It can grow up to 7" tall, 1.75" in diameter. It blooms during the summer with pale to bright yellow up to 1.2" in diameter flowers

Recommended temperature zone: USDA: 9b-11
Sun exposure: Light shade
Origin: Brazil (Rio Grande do Sul, Santana da Boa Vista)
Watering needs: Regular water in summer. Keep rather dry in winter, rot easily if the substrate is wet and cold, tends to lose its roots in winter.

Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz