Cactus Wine

Lore & Background

When Carl Linnaeus published Species Plantarum in 1753 – the starting point for modern botanical nomenclature – he placed all the species of cactus known to him in one genus, Cactus. In 1754, the Scottish botanist Philip Miller divided them into several genera, including Opuntia. He distinguished the genus largely on the form of its flowers and fruits. Considerable variation of taxonomy occurs within Opuntia species, resulting in names being created for variants or subtypes within a species, and use of DNA sequencing to define and isolate various species. The tendency towards hybridization also creates a tendency towards classifying what should be a specific subspecies of Opuntia into one of the larger umbrella species because different variations in form are assumed to be due to hybridization. Opuntia hybridizes readily between species. This can make classification difficult, yielding a reticulate phylogeny where different species come together in hybridization. Opuntia also has a tendency for polyploidy. The ancestral diploid state was 2n=22, but many species are hexaploid (6n = 66) or octaploid (8n = 88).

In Their Own Story

One of the ancient homes of the cactus pear, Mexico, ran a breeding program in the 1960s. This effort at the Antonio Narro Agrarian Autonomous University (Universidad Autónoma Agraria Antonio Narro, UAAAN) produced improvements in some traits including cold-hardiness. Charles Darwin was the first to note that the cacti have thigmotactic anthers. When the anthers are touched, they curl over, depositing their pollen on the pollinator. That movement can be seen by gently poking the anthers of an open Opuntia flower. The same trait has evolved convergently in other genera (e.g. Lophophora). Natural distribution of the plant occurs via consumption and associated seed dispersal by many animals, including antelopes, nonhuman primates, elephants, birds, and humans. When ingested by elephants, the sharp components of the plant cause harm to the mouth, stomach, and intestines.

Reader's Guide

Prickly pears (mostly O. stricta) were originally imported into Europe during the 16th century. They are now found in the Mediterranean region of Northern Africa, especially in Algeria, Morocco and Tunisia, where they grow all over the countryside, and in parts of Southern Europe, especially Spain, where they can be found in the east, south-east, and south of the country, and also in Malta, where they grow all over the islands, and in southern Italy, especially in Sicily and Sardinia. They can be found in enormous numbers in parts of South Africa, where they were introduced from South America. The prickly pear is considered an invasive species in Australia, Ethiopia, South Africa, and Hawaii, among other locations. The first introduction of prickly pears into Australia is ascribed to the founding governor of the New South Wales colony, Arthur Phillip, and the earliest European colonists, in 1788. Brought from Brazil to Sydney, they were most likely O. monacantha. That variety did not spread beyond the east coast. However, a number of other types of prickly pear were introduced to Australian gardens in the mid-19th century. The cactus was also used as agricultural fencing and a feedstock for animals in times of drought, as well as in an attempt to establish a cochineal dye industry. The cactus became a widespread invasive weed in the dry interior climate west of the Great Dividing Range, in New South Wales and Queensland, eventually converting 260,000 square kilometres (101,000 mi2) of farming land into an impenetrable green jungle of prickly pears in places 6 m (20 ft) high. Scores of farmers were driven off their land by what they called the "green hell", and their abandoned homes were crushed under the cactus growth, which advanced at a rate of 400,000 hectares (1 million acres) per year. In 1919, the Australian federal government established the Commonwealth Prickly Pear Board to coordinate efforts with state governments to eradicate the weed. Early attempts, comprising mechanical removal and poisonous chemicals failed. As a last resort, biological control was attempted. In 1925, the Cactoblas...

Did You Know?

• Between 8,000 and 9,000 years ago, the Opuntia prickly pear cactus was domesticated in central Mexico.
• The genus is named for the Ancient Greek city of Opus.
• Charles Darwin was the first to note that the cacti have thigmotactic anthers, which curl over and deposit pollen when touched.
• In Australia, prickly pears converted 260,000 square kilometres (101,000 mi2) of farming land into an impenetrable green jungle, advancing at a rate of 400,000 hectares (1 million acres) per year.
• The ancestral diploid state of Opuntia is 2n=22, but many species are hexaploid (6n = 66) or octaploid (8n = 88).