The medicinal herbs play an important role in the health of human communities. Many of wild plant species have adapted to the climatic conditions of the Iran and are endemic wild species. One of these medicinal plants is Yarrow( Achillea millefolium L) with different medicinal and ornamental uses. A. millefolium is widely spread in Northern hemisphere and Iran. In this study, 10 populations of this plant species from the countries of Iran, Austria, Slovenia, Japan, USA, England (UK), Spain, Lithuania and Canada were evaluated in a randomized complete block design with three replications were studied for some morphological and physiological traits under two irrigation regimes, including 50 and 90 mm evaporation from pan, kashida; TEXT-ALIGN: justify; TEXT-KASHIDA: 0%; TEXT-INDENT: 0in; MARGIN: 0in 0in 10pt; unicode-bidi: embed; DIRECTION: ltr" Key words : Yarrow, Morphological characters, Irrigation regime, Self-pollinated seeds
