Sciophytes are shade-loving trees or plants. These plants have larger photosynthetic units than sun plants or heliophytes. Sciophytes are also known as photophobous plants and they reach their saturation level in only 20% sunlight. Shade-plants essentially follow strategies of optimum use of available energy and conservation of energy. Adaptation to achieve these strategic goals include thinner leaves with a relatively higher chlorophyll content per unit leaf volume; lens-shaped epidermal cells that focus incoming light into and within the mesophyll; a redcell layer that reflects outgoing light back into the mesophyll, and greater allocation of available energy to defence-mechanisms against herbivory.