The influence of morphological differences in bracken pinnules on the foliar uptake of aminotriazole

Bracken growing on an open hillside had greater development of both the upper and lower cuticular membranes than that growing under moderate shade. However, in the latter, aminotriazole uptake was less. This could be due to decreased spreading of the applied solution on the upper surface of shade-grown fronds and a decrease in stomatal and/or leaflet hair densities on the lower surface.