The Alborz Mountains are the second largest mountain range in Iran and possess the tallest peak. Mountain wetlands on the arid southwestern slopes of the Alborz range, as compared to other parts of this range, are relatively unknown botanically. We present here the contemporary status of the flora, life forms, and phytogeographic characteristics represented by 90 sites in these wetlands of the arid mountains. Three hundred and fifty-four taxa were identified, belonging to 201 genera and 54 families. The largest families are Asteraceae (15.3 %), Poaceae (13.8 %) and Cyperaceae (8.5 %). The genera represented by the greatest number of species are Carex (12 species), Galium (9), Epilobium (9), and Cirsium (9). Hemicryptophytes prevail in number (34.2 %), followed by geophytes (29.0 %) and therophytes (20.6 %). From a chorological viewpoint, most of the flora belongs to the pluriregional elements (35.2 %). There are a large number of Irano-Turanian elements within these wetlands, and nearly 6 % of the flora consists of endemic and subendemic taxa. Four main groups of habitats were recognized, corresponding to wet meadows, springs, lakeshores, and river banks. Mountain wetland vegetation in the Alborz Mountains requires strong conservation and protection management policies since they are restricted, isolated, and productive ecosystems.