(a) Flora

The proper desert plants may be divided into two main groups. i ) depending directly upon on rain and

i i) those depending on the presence of subterranean water.

The first group consists of two types:

♤ depending directly upon on the rain are of two types -the ‘ephernerals’ and the rain perennials’.

♤ The ephernerals are delicate annuals, apparently free from any xerophilous adaptations, having slender stems and root-systems and often large flowers. They appear almost immediately after rain, develop flowers and fruits in an incredibly short time, and die as soon as the surface layer of the soil dries up.

♤ The rain perennials are visible above the ground only during the rainy season, but have a perennial underground stem.

♤ The second group - depending on the presence of subterranean water

♤ By far the largest number of indigenous plants are capable of absorbing water from deep below the surface of the ground by means of a well-developed root system, the main part of which generally consists of a slender, woody tap root of extraordinary length.

♤ Generally, various other xerophilous adaptations are resorted to such as reduced leaves, thick hairy growth, succulence, coatings of wax, thick cuticle, protected stomata, etc., all having for their object of reduction of transpiration.