The genus Alyssum L. belongs to the subtribe Alyssinae, tribe Alysseae and family
Cruciferae (Brassicaceae). This genus is one of the largest genera of the family of
Cruciferae in Iran, and seems to be the most problematic genus in which the boundary
of certain species is not completely clear due to the polymorphism of morphological
characters. The main objective of this research is to study the species of the genus
Alyssum using numerical taxonomic methods. Thirty-three Operational Taxonomic
Units (OTUs) belonging to the twenty-nine species of Alyssum L. from Iran were
examined and scored for thirty-six qualitative characters having two or more states.
This work is based on field and different herbarium samples. The data were analysed
by UPGMA clustering method. The results of this study suggest that there are
basically four sections (Meniocus, Odontarrhena, Alyssum and Psilonema) which
can be grouped under two subgenera, namely subgenus Eualyssum and subgenus
Meniocus. The results of cluster analysis were compared with the classification
obtained by conventional methods and the relations among the taxa have been