According to the key (Skvortsov 1999: 170), all leaves in S. aegyptiaca are pubescent beneath with white or grayish trichomes that are deviating off leaf blades (as in S. caprea ); pubescence at second- and third-order veins, if any, is not denser than between veins (while in S. atrocinerea pubescence is conspicuously denser on veins than between veins).