About Harrisia martinii (Labour.) Britton
Harrisia martinii is a richly branched cactus with spreading green to gray-green shoots. Shoots can reach lengths of up to 2 meters or more, with diameters between 2 and 2.5 centimeters. Young shoots are tapered to a point and have four to five edges, while older shoots are round in shape. This species produces one strong, yellowish central spine per areole that has a darker tip and measures 2 to 3 centimeters long. Its five to seven marginal spines are noticeably shorter than the central spine. The flowers of Harrisia martinii can grow up to 20 centimeters long, and their pericarpel is covered in scales and brown wool. The fruits are more or less spherical, red, tuberous, and have both scales and thorns; these red globular fruits are edible. Harrisia martinii is widespread in Chaco vegetation, growing at elevations between 50 and 100 meters in Paraguay, and in the Argentine provinces of Formosa, Chaco, Corrientes, Entre Ríos, and Santa Fe. The first recorded finding of the species in Brazil was in 2007. It is classified as an exotic invasive species in Australia, South Africa, and the U.S. state of Hawaii.
