Prickly Pear Overview
Opuntia is a genus of around 132 species of creeping, perennial, bushy or tree-like cacti in the Cactaceae family. These plants are native to the Americas but widely naturalised in non-native regions. Commonly known as Prickly Pears, they have flattened pad-like stem segments covered with spines and barbed bristles. Flowers are funnel-shaped followed by pear-shaped fleshy and spiny fruits that in some species are edible. Prickly pears typically grow with rounded cladodes, which are flattened stems that resemble and function as leaves and are armed with two kinds of spines: large, smooth, fixed spines and small, hairlike prickles called glochids, that easily penetrate skin and detach from the plant. Many types of prickly pears grow into dense, tangled structures. Charles Darwin was the first to note that these cacti have thigmotactic anthers: when anthers are touched, they curl over, depositing their pollen. This movement can be seen by gently poking the anthers of an open Opuntia flower. In cooler climates, Opuntias can be grown under glass but are not advised as house plants as the spines and bristles can cause severe skin irritation.