Echinocereus ingens
(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).
Description: It is a slowly growing massive barrel cactus usually solitary that grows huge in habitat (up to 2.5 m tall, 1.5 m wide). It could live more than a hundred years. This cactus is easily recognized by it's large size, being the largest of all barrel cacti.
Flowers: Diurnal, vivid yellow.
Blooming season: From end of spring to summer only on larger mature specimens receiving enough full sun.
Cultivation and propagation: Frost tender but resistant to -4°C for short periods. Cold hardiness increases with improved drainage, so keep plants as dry as possible in winter. They grow best in well-drained soil and a position in full sun, which will help to maintain the luster of the spines and longevity of the flowers. Provide the plant with extremely well-drained soils, as the plant are subject to crown and soft rot if it remains too moist.
Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz