The main tasks of this group are comparative taxonomic investigations of living and reference collections by studying different morphological and anatomical characters resulting in phylogenetic conclusions, the construction of classifications, and nomenclatural work. The studies target general problems of the taxonomy of crop plants. Most recent results were incorporated in the recent edition of "Mansfeld's Encyclopedia of Agricultural and Horticultural Crops".

The group is responsible for the botanical reference collections. The custodial management of the reference collections (400,000 herbarium sheets, more than 95,000 samples in the seed and fruit collection, and approximately 51,000 cereal spike samples), as well as preparation, labelling, and arranging of the specimens according to classification are continuous activities. By collecting, exchange and adding new accessions from the genebank, the archives are annually enlarged by 3,000 to 4,000 specimens. These collections are frequently used by colleagues from other institutions in Germany and abroad. They can be searched in parts online: Herbarium IPK Gatersleben (GAT).

The staff contributes to the characterisation of genebank material by taxonomically revising newly acquired accessions and is engaged in collecting missions if demand exists. The taxonomists have special knowledge and long-lasting experience in the genus Allium and are entrusted with the taxonomic supervision of the living Allium reference collection of the genebank (more than 1,800 definitively determined accessions of 360 species and about 25 closely related taxa). The taxonomists take part in an international research project on pharmacologically interesting wild Allium species funded by VolkswagenStiftung. They are responsible for correct determination of the analysed materials and will train the co-operating partners from 4 foreign institutions in the management of collecting missions and in the establishment of living national Allium collections.

Joint research activities with the Research Group Experimental Taxonomy consist in application of specific methods for joint research themes. Current activities focus on the study of natural diversity and plasticity of Arabidopsis thaliana (L.) Heynh. (funded by DFG) which started in 2001. Field work in Uzbekistan showed that this species is rather rare and ecologically much more specialised contrary to data in the literature. The remarkable morphological and ecological diversity among accessions from different regions is studied currently. An unexpected result was a remarkable morphological similarity between A. thaliana and plants related to Arabis auriculata Lam. when they were growing in very poor conditions.