Harrisia gracilis is a species of cactus found in Jamaica.
Harrisia gracilis grows shrubby, is richly branched and forms groups with upright to spreading shoots. The green, cylindrical shoots are greatly elongated. They have diameters of 2.5 to 4 centimeters and reach lengths of 3 to 5 meters. There are nine to eleven ribs. The seven to 16 thorns are spread out, straight, strong and needle-like. They are grayish ocher or gray, almost completely covering the shoots and are up to 2.5 centimeters long.
The flowers reach a length of 15 to 20 centimeters and a diameter of 10 to 12 centimeters. Its flower tube is covered with soft, white hairs. The yellow, smooth fruits are covered with a few hair-like thorns. They have a diameter of 3 to 6.2 centimeters and reach a length of 3 to 4 centimeters.[1]
Harrisia gracilis is common in Jamaica.[2]
It was first described as Cereus gracilis in 1768 by Philip Miller.[3] The specific epithet gracilis means 'delicate, slim, thin'. Nathaniel Lord Britton placed the species in the genus Harrisia in 1909.[4] Other nomenclature synonyms are Cactus gracilis (Mill.) Weston (1770) and Echinopsis gracilis (Mill.) Molinari & Mayta (2015).