(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).
Description: Melocactus curvispinus is highly variable in shape, it has has been divided into several species and subspecies by hobbyists, but only 3 subspecies are valid (subsp.curvispinus, subsp.caesius and subsp. dowsonii).
Habit: Usually solitary.
Blooming season: spring to summer open late in the afternoon.
Recommended temperature zone: USDA: 11-12
Frost tolerance: Does better if kept above 60°F (15°C) in winter
Minimum avg. temperature: 60°F (15°C)
Sun exposure: Light shade
Origin: Guatemala, Honduras, Mexico (Chiapas)
Growth Habits: Up to 8 inches tall (20 cm)
Watering Needs: Moderate water
Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz