Fig 2. Placement of eight landmarks on dissected side view photographs of Arabis alpina flowers.

Photos are representative examples for each of the three selfing populations (top panel) and the three outcrossing populations (bottom panel). Numbers indicate landmarks: 1—base of short left stamen; 2—base of pistil; 3—base of short right stamen; 4—anther tip of short left stamen; 5—stigma tip; 6—anther tip of short right stamen; 7—anther tip of long left left stamen; 8—anther tip of long right stamen. Within one of the pictures, lines indicate the measure taken based on the landmarks: average herkogamy long stamens (red lines) as (a+b)/2; average herkogamy short stamens (blue lines) as (c+d)/2; average length long stamens (orange lines) as (f+g)/2; average length short stamens (orange lines) as (h+i)/2; average angle long stamens (red double dashed line) as (α+β)/2; average angle short stamens (red double dashed line) as (γ+δ)/2.