Non-succulent perennials
These are actually the true xerophytes or drought resistants, because they possess a number of morphological, anatomical and physiological characteristics which enable them to withstand critical dry conditions. They exhibit rapid root growth and form an extensive root system to tap water from the soil in a most efficient manner. The leaf size is greatly reduced and in many xerophytic grasses, leaves roll on to reduce the leaf surface for restricting loss of water due to transpiration. Some of the examples are Calotropis procera, Acacia nelotica, Saccharurn munja In non-succulent xerophytes, root system is very extensive e.g. Calotropis. Important adaptations to minirnise the loss of water through transpiration are:
- thick waxy coating on leaves.
- thick cuticular and epidermal layers.
- leaves small, sometimes scaly or survive for a short period only.
- leaves modified into spines or in exueme cases stem devoid of leaves.
- dying back of leaves is a common phenomenon in many grasses.
- rolling and folding of leaves as seen in many grasses.