Environmental modifications of leaf surface traits in Datura stramonium

Abstract

Studies of cuticular modifications of leaves by the environment were conducted on Datura stramonium L. (Blakeslee seed lot, box 8-451) to determine the degree of constancy of cuticular features when plants were subjected to different environmental conditions. This species was considered to be a highly inbred line with a high degree of genetic constancy. The plants were subjected to five environmental conditions, from xeric to very humid. Sinclair and Dunn's method (reported in 1961) of making plastic cuticular imprints was used. It was concluded that the stomatal size classes, mean stomatal size, subsidiary cell complex, pattern of stomatal development, and the type of trichome and trichome distribution pattern were consistent. Stomatal index was generally reliable, except under extreme environments where the plants probably would not have survived in nature, under competition. Stomatal frequency, epidermal cell frequency, and trichome frequency were inconsistent under the different environmental conditions. The total leaf area was so easily modified that absolute stomatal numbers described by Gupta in 1961 were not worth calculating.