Characterstics of CAM Plants

Characteristics of CAM Plants are as under.:-

·        CAM Plants are succulent xerophytes belonging to some dicot families  such as Crassulaceae, Cactaceae, Euphorbiaceae, Asclepiadaceae, etc and some monocot families such as Agavaceae, Liliaceae, Orchidaceae, etc.

·        These plants follow a characteristic CAM pathway during dark reaction (biochemical phase) of photosynthesis.

·        It was first observed in plants of family Crassulaceae and hence described as Crassulacean Acid Metabolism (CAM) pathway.

·        CAM plants show a number of structural (anatomical and morphological) adaptations to suit the dry and hot habitat (desert adaptations). These adaptations are:-

(a)  Thick and fleshy (Succulent)organs for water storage.

(b) Excessive formation of storage parenchyma.

(c)  Thick cuticle, epidermis and hypodermis.

(d) Stomata closed during day time to check transpiration.

(e)  Gaseous exchange through open stomata during night only.

·        These plants also show  a number of physiological adaptations to suit the xerophytic conditions , e.g.

(a)  CAM pathway for Dark reaction of photosynthesis.

(b) CAM plants compete Dark reaction of photosynthesis in two parts (i) night photosynthesis activity (C-4 cycle).(ii) day photosynthetic activity (C-3 cycle).


(c)  CAM plants have comparatively slower rate of photosynthesis (due to closed stomata during day time) and hence their growth is slow.