(also heliophyte), a plant that grows in open places and cannot withstand long periods in the shade. For normal growth, photophilic plants require intense solar or artificial radiation. Adult plants of this type require more light than younger plants. Photophilic plants include herbs (broad-leaved plantain and water lily), arboreal plants (larch and acacia), early-spring steppe and semidesert plants, and cultivated plants (corn, sorghum, and sugarcane).
Photophilic plants have a number of special anatomic, morphological, and physiological features. They have relatively thick leaves with fine-celled columnar or spongy parenchyma and a large number of stomata. There are 50 to 300 small chloroplasts in the leaf cells; their surface is ten times greater in area than the surface of the leaf. Compared to the leaves of shade plants, those of photophilic plants contain more chlorophyll per unit area but less chlorophyll per unit mass of the leaf. The characteristic physiological feature of photophilic plants is a high rate of photosynthesis.
I. A. SHUL’GIN