Study Of Phyto-Geographical Distribution Patterns And Endemism Of Genus Psychrogeton (Asteraceae) From Pakistan (Including Kashmir), Iran And Afghanistan

Abstract

 Study of distribution patterns and endemism of 19 species of Psychrogeton Boiss.of the tribe Astereae, (Asteraceae) have been carried out. A total of 19 species are recognized from the region. Out of which, 6 species are recognized from Pakistan & Kashmir, (Fl. of Pakistan, 224, 2021) while 13 from Afghanistan and 11 are recognized from Iran. Out of 6 taxa reported from Pakistan, 3 elements are strictly Sino-Japanese, 3 taxa are reported from both regions Sino-Japanese and Eastern Irano-turanian. From Afghanistan out of 13 species, seven are reported in both Sino-Japanese and Irano-Turanian phytochorions, while  five are restricted to Irano-Turanian and two species are found in Sino-Japanese only. Iran and Afghanistan both countries consist mainly of Irano-Turanian phytochorion while Iran has small Saharo-Sindian area in its Sistan & Balochistan province and Afghanistan has Saharo-Sindian region extended to Qandhar, Helmund and Nimruz and Sino-Japanese region includes the provinces of Lougar, Nangarhar, Kabul, Kunar, Nurestan, Kapisa, Laghman  and Panjsher. Phytogeographically, there are 21.05 % species which are pluri-regional, (four species) and found in all the three countries, only these four species are shared by Iran and Pakistan. 15.78 % taxa (1 species), are bi-regional, found in two countries e.g. Pakistan and Afghanistan, two species are shared by Iran and Afghanistan. There are 60 % species (12) which are uniregional, 6 species are endemic to Afghanistan, 5 species are endemic to Iran, one species is endemic to Pakistan.

Key Words: Pakistan, Iran, Afghanistan, Phytogeography, Psychrogeton, Astereae, Asteraceae.