Leaf stomatal density (SD), net photosynthetic rates (PN), and stomatal conductance (gs) of Hordeum vulgare and Pisum sativum cultivars in Himalaya increased with altitude. Higher PN and leaf temperature under low CO2 partial pressure at high altitudes could evoke a higher gs and SD to allow sufficient influx of CO2 as well as more efficient leaf cooling through transpiration. and S. K. Vats, N. Kumar, S. Kumar.