(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).
Echinopsis ancistrophora ssp. arachnacantha
The species name "arachnacantha" comes from the Greek for "with spider web-shaped thorns". This cactus still generally encountered under its older Lobivia arachnacantha name is a good beginner cactus. It is quite resistant and occasionally gets covered by bright yellow blossoms, that will attract even a non-cactophile spouse.
Recommended temperature zone: Sunset: 16, 17, 21-27, USDA: 9b-12
Frost tolerance: Hardy to 25°F (-4°C), for short periods
Minimum avg. temperature: 50°F (10°C)
Sun exposure: Full sun to light shade
Watering needs: Regular water in spring to fall
Blooming habits:The large 2" wide yellow flowers open during the day.
Requires to be kept below 45°F (7°C) in winter to flower well in the spring.
Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz