Chromosome numbers of some annual Veronica (Plantaginaceae) with report of V. tenuissima from flora of Iran

Somatic chromosome numbers of 20 accessions belonging to 10 species of Veronica are counted from Iran. Chromosome numbers of three species are reported for the first time ( V. intercedens 2n=2x=14, V. macropoda 2n=2x=14 and V. tenuissima 2n=4x=28) and hitherto unknown ploidy levels are also reported in V. biloba (6x) and V. capillipes (6x). Chromosome count in V. intercedens suggests a basic chromosome number of x=7 for V . subsect. Cardiocarpae . It was realized that polyploidy (sometimes with variable ploidy levels) is very common among members of V . subgen. pocilla which was assumed to be a major factor responsible for different ecological tolerances, allowing these species to inhabit harsh environments and in some cases even invade new habitats beyond their native ranges. Failing to detect diploid specimens, particularly of V. campylopoda , led us to the conclusion that diploid ancestors of some of these polyploid races are either already most likely gone extinct or restricted to some small refuge areas. Veronica tenuissima is also reported from Iran based on materials from south‐east of country. Photographs of living plants and distribution map of V. tenuissima are provided and its conservation status is estimated.