Divergence in leaf morphology and physiology in Andropogon gerardii var. hallii (sand bluestem) a locally adapted variety of Andropogon gerardii (big bluestem)

Cuticular waxes are the initial point of contact between plant interiors and the aerial environment. They mediate non-stomatal water and gas exchange; adhesion and penetrance of biotic pathogens; wettability; and light reflectance. We focus on the epicuticular (outermost) waxes of two interfertile grasses with overlapping ranges that exhibit a high degree of morphologic divergence. Sand bluestem is locally restricted to sandy soils with low nutrient and water content (Fig A, B, and C.) Big bluestem establishment is restricted to moister, nutrient rich prairie soils (Fig A, B, and D).