Love Drought Trivia Quiz

Answer: To establish a cochineal dye industry

Australia's dry country looked like the perfect area for prickly pears, which were imported and used in the outback to provide shade, and act as a natural barrier to encourage sheep and cattle to stay in a relatively controlled area. Older plants were also cut down and dried for use as fodder.

However, the prime reason for the species chosen (mostly Opuntia stricta) was that they are the favorite plant of the cochineal, a scale insect that feeds on Opuntia plants. They are scraped off the pads, and collected to produce the food coloring and dye called carmine or cochineal.

At the time, this was a thriving industry, but the development of artificial dyes during the late 19th century led to a sharp decrease in demand, and the bottom fell out of the market.

The prickly pears remained, and thrived, but lost their original useful purpose.

Answer: The nopal plant has a fruit called tuna

Opuntia ficus-indica is the scientific name for the prickly pear which is most commonly eaten. In its native Mexico, it is called the nopal plant, from the Nahuatl word for the fleshy pads which characterise its appearance, and the fruit is called tuna.

Not the fish. The vaguely pear-shaped fruit is the source of the English name prickly pear - and they are indeed prickly! They are a common food for both people and livestock, and have traditional medical uses (has anyone else seen late-night infomercials for nopal extract?) including possible anti-inflammatory properties, and as a means of lowering blood sugar and cholesterol levels.

These claims are based on anecdotal evidence, and have not been verified by systematic testing.

Answer: Mexico

Also called nopal tapon, this is a relatively low and spreading cactus, with large round paddles, which usually reaches a height of around a metre (three feet). It gets its name from the barrel-shaped fruit, which are usually pink to red to purple in color, and up to 8 cm (3 inches) long.

The flowers are usually yellow and sessile (meaning they are attached directly to the paddle, and have no stem). Although not native to Australia, they love the climate, and have been officially declared a pest weed in several states.

Answer: Moonlight cactus

There are about 20 species of the genus Harissia (named after William Harris, a Jamaican biologist), which are also called applecactus in some of the areas to which they are native - along the eastern coast of South America and some Caribbean islands.The common name applecactus refers to the appearance of their fruit, while moonlight cactus is based on the fact that the flowers are best seen by moonlight, when they open. Like most members of the cactus family, they have lots of spines (which are considered to be modified leaves), and a succulent (water-holding) stem.

Answer: Velvet tree pear

Since it was imported near the end of the late 19th century, the velvet tree pear has established itself securely over large areas of inland New South Wales and Queensland. Although it was declared a noxious weed long ago, it had been tolerated by most farmers, since other Opuntia species are a more serious problem, and the cost of pesticide treatment for something that can be ignored (and even used as fodder in extreme drought times) simply isn't worth it. Recently, however, some areas where it is so abundant that other, more desirable plants, cannot grow have started to take action to control them.

The tree has leaves which are smooth when young, but which develop a furry surface as the tree matures - hence its name. It can be recognised by its height, by its lovely orange-red flowers, and by the massive numbers of fruit it bears. Birds love the fruit, and their droppings distribute the seeds widely.

Answer: Invasive plant

Australia has a lot of invasive species, both of plants and of animals, as the early European settlers brought along (or had sent over) the plants and animals with which they were familiar at home. Hence the rabbit plague which has been a problem for farmers ever since the first ones, brought over to provide some sport shooting, escaped.

Not many of the plants developed into invasive species, as the Australian climate did not encourage them overmuch, but the imported xerophytes have thrived. The image for this question, taken in 1950, showed the sign erected to show that the nearby Harrisia had been poisoned, so the area should be avoided while the poison was active.

Answer: Cactoblastis moth

There have been a number of unsuccessful attempts at biological control in Australia, including the fateful decision to import the cane toad to control the local grey-backed cane beetle which affected sugar cane crops. They have taken a terrible toll on native fauna as they have spread across the country - their toxins are lethal to native species which have no natural defense against it. The use of the myxoma virus to control feral rabbits in the 1950s was initially successful, with over 90% of the population being eliminated. Over time, however, the survivors, who were naturally resistant to the virus, bred to produce a new rabbit population that was more resistant to the virus, and it became virtually useless by the 1990s, when over half the rabbit population was carrying the virus without suffering any ill effects. Subsequently other viruses have been developed, but so far all have shown a similar pattern of initial success followed by developing immunity.

The importing of Cactoblastis cactorum (native to the east coast of South America) in 1925, however, was highly successful in controlling prickly pear, which led to other countries introducing it as a biological control.

Answer: Hooky bush

This perennial shrub has (relatively) large thorns, usually over 2 cm (an inch) in length, that resemble the kind of hook on which one might hang a coat on entering the house. Its white flowers form in clusters at the base of the spines. The other endemic member of the genus, Discaria nitida, has shorter spines, and is deciduous, while D pubescens has few if any leaves. Both plants bear some resemblance to imported plants that are considered weeds, and are sometimes eliminated by mistake.

The image for this question is actually of Discaria toumatou, which is endemic to New Zealand. The Australian relatives are more upright, but just as thorny.

Answer: Round-leaf Pigface

The species Disphyma crassifolium grows in salty-soil regions (such as coastal dunes) in New Zealand, Australia and South Africa. The South African plants are now considered to be a different subspecies (D crassifolium crassifolium) from those found in Australia and New Zealand.

Their pink-purple flowers have led to them also being called purple dewplant. There is another Australian native with purple flowers called pigface, or angular sea-fig, but it is not particularly closely related to round-leaf pigface, having the species name Carpobrotus glaucescens.

They are in the same family, Aizoaceae, also called the fig-marigold family. This family of succulents has flowers that resemble marigolds, and fruit that looks somewhat fig-like.

Answer: They get larger and thinner as the plant grows

Peperomia blanda is found in tropical areas around the world. Typically it is a perennial plant, herbaceous rather than woody, and ranges in form from ground covering to creeping plants that can grow up to several feet in height. The Australian species have young plants whose leaves are very succulent, with rounded and fleshy leaves, as seen in this immature plant.

As it grows, the leaves become longer and thinner, so much so that an adult looks as if it is an entirely different plant to the untrained eye.