Harrisia tetracantha
Harrisia tetracantha is a species of cactus found in Bolivia.
Description
Harrisia tetracantha grows in a shrub-like to tree-like manner, is usually branched above the ground and reaches heights of up to 3 meters. The blue-green to gray-green shoots have a diameter of up to 6 centimeters. There are eight rounded and tuberous ribs. The single, strong, initially brownish central spine later becomes white to ash-gray. The four to seven white marginal spines have a brown tip.The flowers reach a length of 18 to 22 centimeters.