Illicium verum Hook. f. and Illicium anisatum L.: Anatomical Characters and their Value for Differentiation

In the last years intoxications after consumption of Illicium verum Hook. f. have been reported due to adulterations with I. anisatum L.. Many efforts have already been made to develop a simple method which would enable the detection of I. anisatum in powdered samples of I. verum. Since many controversial facts concerning the value of anatomic characters for differentiation have been published 13 botanically vouchered samples were re-examined by means of light microscopy, fluorescence microscopy, SEM, and confocal laser scanning microscopy. All anatomical details show a great variability even between the follicles of a certain aggregate. This is also true for the cuticular striation which has been proposed in literature as reliable character. Special attention was paid to the structure of the aleurone grains of the endosperm and the shape of the calcium oxalate crystals in the testa. In contrast to previous assumptions these characters do not allow a certain differentiation either. However, the presence of hexagonal crystals can serve as indicator for samples of I. anisatum. At present a reliable proof of purity of powdered samples of I. verum seems to be possible by chemical analytical methods only.