Blue Lupine

April 29, 2019



Photographer: Menashe Davidson 
Summary Author: Menashe Davidson 

Walking among the beautiful flowers of blue lupine (Lupinus pilosus) on Lupine Hill, Emek Haela, Israel, I was fascinated to watch the floral color changes in fully blooming turgid flowers. The lower flowers on the stem, the ones that first open, were nearly pure blue, while the young flowers above had white banner spots on the blue petals. These banner spots are signals for pollinators to avoid the older flowers (even though the individual flowers don’t wilt), thereby increasing pollination efficiency. The color change appears to be brought about by ethylene production as the banner spot pigment accumulation is accelerated. Note that banner color change seems to be sped up by pollination and probably deters further insect visits, therefore avoiding unnecessary wastage of pollen. Endemic to Israel, these eye-catching flowers will bloom from February to May. Photo taken on February 28, 2019.