About Harrisia pomanensis (F.A.C.Weber ex K.Schum.) Britton & Rose
Harrisia pomanensis is a cactus species that sometimes grows in a somewhat bushy form. Its shoots are more or less upright, occasionally arched or prostrate, and range in color from blue-green to gray-green. They are glaucous, nearly round in cross-section, and measure 2 to 4 centimeters in diameter. This species has four to seven blunt, rounded, non-humped ribs along its shoots. Its thorns are needle-like; they start out reddish to almost white, and later turn gray with black tips. There is one single central spine, which is 1 to 2 centimeters long. The six to eight marginal spines grow up to 1 centimeter long. The flowers of Harrisia pomanensis can reach up to 15 centimeters in length. Its fruits are spherical, slightly bumpy, red, and bear a small number of scales. Harrisia pomanensis is naturally widespread across southern Paraguay, Bolivia, and northern Argentina, where it grows at elevations between 200 and 1200 meters. It is classified as an exotic invasive species in Australia.
