Family: Cactaceae

There are about 200 species in this genus which has a wide geographical spread, from southern Canada, throughout the Americas, and south to the Straits of Magellan. Many local, common names have been adopted, more familiar ones being prickly pear, cholla and tuna.

Opuntias are jointed or segmented cactuses with mainly padded, flattened joints and they may be cylin­drical or rounded in shape. Some, such as the prickly pear or Indian fig, Opuntia ficus­indica, have edible fruit. This species is grown for its fruits in many tropical and subtropical parts of the world. In some places it has become naturalized. There are also large numbers of smaller species of various shapes and sizes pop­ular with cactus enthusiasts. Many make good container plants.

Opuntias flower in spring or summer, depending on the species and district. Many have yellow flowers. Berry-like fruits that form after the flowers have faded are edible in some species. Long grown as living fences in their native areas, many were introduced to other countries for this purpose with devastating results.

Species like O. aurantiaca, 0. stricta and O. vulgaris became appalling weeds in Australia, Africa and India. After years of concentrated effort, many infestations are under control but constant vigilance is needed to prevent prickly pear from getting out of hand.

Species

O. basilaris, beaver tail, grows about 40 cm (16 in) high, with purple-gray flat pads and red-purple flowers in summer.

O. bigelovii, known as teddy bear cholla (pronounced 'choya'), is densely covered with spines that appear furry. It grows 1-2 m (3-6 ft) high.

O. erinacea is a clump-forming cactus with flattened, blue-green pads. Var. ursina, with masses of fine, hair-like spines, known as griz­zly bear cactus, is the more popular.

O. ficus­indica, Indian fig, is almost tree-like, growing 3-5 m (10-16 ft) high, with large, segmented, paddle-shaped leaves and bright yellow flowers that mature into deep red or purple fruit.

O. microdasys has dark green pads dotted with white areoles, and bristles that may be white, yellow or brown. The form that is brown-bris­tled is known as teddy bear ears.

O. tunicata makes a small, spreading bush, 60 cm (24 in) high and 1 m (3 ft) wide. It has thick, creamy, satiny spines and bright, yellow flowers in summer.

Cultivation

These plants are easily propagated from stem segments separated from the parent plant and can also be grown from seed sown in spring. In frost-prone climates, grow in a cool greenhouse or conservatory in pots of cactus compost, with maximum light. Keep dry in winter and water normally at other times. Outdoors, grow in a sunny, well-drained spot.

Climate

Mostly zone 9.