Janna Akopian - A. Takhtajan Institute of Botany of the National Academy of Sciences of the Republic Armenia, Yerevan, Republic of Armenia
Araksja Elbakyan - A. Takhtajan Institute of Botany of the National Academy of Sciences of the Republic Armenia, Yerevan, Republic of Armenia
Lora Martirosyan - A. Takhtajan Institute of Botany of the National Academy of Sciences of the Republic Armenia, Yerevan, Republic of Armenia
Zhanna Hovakimyan - A. Takhtajan Institute of Botany of the National Academy of Sciences of the Republic Armenia, Yerevan, Republic of Armenia
Anahit Ghukasyan - A. Takhtajan Institute of Botany of the National Academy of Sciences of the Republic Armenia, Yerevan, Republic of Armenia

Psephellus erivanensis Lipsky (Asteraceae) is a threatened knapweed species of the Armenian flora, endemic to the Atropatene floristic sub-province of the Armeno-Iranian floristic province. According to the results of the conducted study, P. erivanensis is identified as a polycarpic rhizomatous hemicryptophyte with perennial rosettes and annual leafy elongated generative shoots. The diploid cytotype has been found for the species to be ۲n=۳۲, the karyotype is symmetric, consisting of ۲ pairs of submetacentric and ۱۴ pairs of metacentric chromosomes, ۰.۷۷-۱.۵۴ µm in size. The average pollen fertility of P. erivanensis is quite high and is in the range of ۹۳-۹۹%, which indicates a high seed set, contributing to the species' reproduction. Plants introduced in the Yerevan Botanical Garden have a full development cycle, mature seed formation, and vegetative self-renewal ability, in comparison with natural ones, are distinguished by higher total humidity, intensity of transpiration and photosynthesis, and a decrease in water deficit. The species is recommended for ex-situ conservation through living plant collection creation and, considering its ornamental value, for utilization in arid landscaping schemes. The article is illustrated with a map of the species distribution in Armenia, original photographs, and tables.

Psephellus erivanensis, conservation, Eco-physiology, Morphology, reproductive features, Armenia