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The Sefid-Kouh protected area is situated 67 km to the northwest of Khorram-Abad . It covers an area of 69500 hectars. Much of the area contain a mountain system between 1500-2854 m altitudes. The aim of this research was to identify the plant species, introducing the flora, detennination of life forms, and geographical distribution in central part of the Sefid-Kouh protected area. For this purpose, plant samples were collected from different parts of the area during two growing seasons between 1997-1998. The biological spectrum of the area was plotted by means of life forms results. The position of the protected area within Iran's phytogeography classification was studied based on geographical distribution data and references. From a total of 148 species and subspecific taxa, 1 fern, 115 dicotyledones and 32 monocotyledones were identified. Among the 47 families represented in the area, the followings had the highest number of species: Asteraceae, Liliaceae, Lamiaceae, Rosaceae and Poaceae. 98 species (66.2%) were endemics of Irano- Turanian region,
17 species of them were endemics of Iran. Distribution of the following species is mainly limited to Zagros area: Alcea koelzii, Amygdalus elaeagnifolia, Arum
giganteum, Centaurea phlomoides, Dionysia gaubae, Pyrus glabra, Quercus brantii var. persica. Hemicryptophytes, geophytes and therophytes with 52 species (35.1 %), 37 species (25%) and 33 species (22.3%) were respectively the most frequent life forms of the protected area.