How complicated actually is genus Ornithogalum?

In most of the studies, genus Ornithogalum is characterized as „complicated“, and species are defined as conspecific. This common in large sections such are sect. Heliocharmos, Albuca, Dipcadi, which have more than 30 species within them. The issue is evident if different identification keys are compared. Even species that have specific characteristics, i.e. O. oligophyllum, O. refractum, can easily be misidentified. In the same time, some investigations simplify genus diversity, aiming to describe most of infrageneric taxa as monophyletic. In that sense, from Ornithogalum sensu lato, 19 genera are recognized as monophyletic groups, with claim that they are easily recognized at morphological level as well. Other studies suggest that caryotype evolution went beyond phenotypic evolution. This is one of the explanations why caryotype diversity is above species diversity. All these „complications” and inconsistencies in Ornithogalum taxonomy caused the need to change the problem focus. Ornithogalum s.l. is distinguished with simple morphology. In general, genus and it representatives can be described with few informative characteristics. Problem arises after 19th and 20th century, when more than 150 species were described only in sect. Heliocharmos. Based on that, in this study we try to find out which morphological characteristics are taxonomically important, and can be interpreted efficiently in identification key. We focused on sect. Heliocharmos, distributed in Mediterranean region, and far on the east, north and west of Asia and Europe. Material used for analysis is from Balkan Peninsula, Pannonia plain and neighboring regions. Overall, 26 species, 72 quantitative and 18 qualitative morphological and micromorphological characteristics are analyzed on fresh and pressed herbarium material. For analyses were used Multiple Correspondence Analysis, Principal Component Analysis, and Discriminant Function Analysis, all performed in Statistica ver. 13.3. Taxonomically important characters for morphological recognitions of sect. Heliocharmos and its species are presented, followed by combinations of characters that are useful for description of series or aggregates. In addition, characters that are too variable for quality interpretation, or cannot be recognized in dry specimens and in every phenophase are highlighted, as insufficiently descriptive. At the end, general identification key for sect. Heliocharmos is presented.