Characterizing traits of a species in its habitat is substantial for planning a practical conservation program. Acanthophyllum ejtehadii Mahmoudi & Vaezi (Caryophyllaceae) is a recently established endemic species for flora of Iran and has a narrow non-conserved natural habitat in Radkan region of Chenaran, Razavi Khorasan Province. The soil and climate of Radkan was studied and the ecological, morphological, anatomical, and karyological aspects of A. ejtehadii were investigated to obtain a comprehensive knowledge about this species and its natural growth conditions. Field observations were performed during the growing seasons in 2014 2015 and 29 vegetation samples were collected as data. Results showed that this plant grows in mound-like sites on clay-loam soils at mean elevation 1279 m.a.s.l. in arid climate. Acanthophyllum ejtehadii is a thorn-cushion form chamaephyte plant. This Plant grow gradually in early-January, the flower unfolds in early-June and the matured seeds are produced in mid-July. A. ejtehadii is a diploid (2n=2x =30) species and has homogenous karyotype. Having unique morphological and anatomical adaptations such as expanded surface roots, reduced leaf area and thickened cuticle, this plant grows successfully in harsh environments. These mechanisms are specific to this specific kind of Acanthophyllum species. The Speciation time of this plant was estimated not more than 200 thousand years ago and if Radkan is preserved from anthropogenic disturbance, this species could expand its distribution area.

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