The upper part of the illustration shows the different appearances of Achillea lanulosa-populations like the variance in the plants' heights cultivated under identical standard conditions in climatic chambers. The lower part of the illustration gives the natural geographic origin of the single populations by way of a profile of a west-to-east cross-section through California; to the left: Sierra Nevada, to the right: Great Basin (J. CLAUSEN, D. D. KECK, W. M. HIESEY, 1948)
