Question

Explain the characteristic of cactus.

Answer 1

Hint: Cactaceae family comprises various species of cactus. These are spiky plants, some of them having bright flowers. They are xerophytic plants. They can survive hot and water-scarce conditions for long periods of time.

Complete answer: Cacti are a large family of xerophytic plants. They are drought-resistant plants that can grow in extreme hot and water-scarce regions. The cactus ranges from small spiky plants to giants. These plants have green stems that are modified to retain and store water. Therefore, the stems are swollen. Also, the roots of the cactus are succulent and penetrate deep inside the soil to reach low groundwater levels. The leaves of the cactus plant are modified to become needle-like and spiky. This is due to less water availability and high temperature. The flat-leaf surface causes more evaporation of water but the spike retains water loss and decreases evaporation as it is a surface phenomenon. Cacti also bear beautiful vibrant coloured flowers. Cactus has areoles that are a characteristic feature of these plants. The areoles are woolly or hairy areas that are present on stems from which the spine emerges. Flowers are also produced from areoles. The various adaptations of cactus allow them to survive harsh desert conditions. Various characteristics of cactus in key points are:
a. Cacti are succulent type plants that are adapted to dry or desert-like areas.
b. CAM or Crassulacean acid metabolism pathway is used for photosynthesis.
c. Many cacti have a specialized waxy and ribbed surface that covers them externally.
d. Spines are the characteristic features of the cactus. The spine protects the cactus from insects and animals. Also, they minimize the surface area to reduce water loss.
e. Cactus bears brightly coloured flowers that are short-lived.

Note: Cactuses are commonly being confused with other succulent plants. But the unique flowers they bear and the spines they have differentiates them from other succulents. Cactus has diverse habitats due to their tough modifications. It belongs to a family comprising about 127 genera with some 1750 known species.