(This plant comes in a 3.5 inch 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).
A common name includes Hedgehog cactus.
Flower: Yellow, with a deep red center.
Blooming season: Summer to Fall.
Cultivation and propagation: This species is easy and well worth growing. It requires little care once they have reached a nice flowering size. Thelocactus setispinus is suited for any rich, well-drained soil in full sun throughout the year (but does better with some light shade in the summer).
This plant needs plenty of water (indicatively to about once a week). Avoid wetting the bodies of these plants while they are in sunlight. A wet cactus in the sunlight can cause sun burning which can lead to scars or even fungal infections and death.
Frost tolerance: In winter keep completely dry at 5°C this usually aids in maintaining a healthier plant, but it is hardy as less as -12 to -7°C depending on the origin.
Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz