Parodia chrysacanthion

Also known as Golden Powder Puff.

Flower: The crown bears a mass of large golden flowers in spring and, often, pale yellow wool.

Blooming season: Spring.

Cultivation and propagation: Water these plants regularly This plant should remain rather dry at other times (especially in winter), except for a quick, periodic misting on warmer days in late winter. If it is kept absolutely dry for a long period, it tends to lose its roots in winter. It can tolerate light frost (- 4C°), but rots easily if wet and cold.
If the local climate is warm enough to grow this plant outside, be sure that soil is well drained and sun if full, but with protection from strong midday rays.

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