Quote - Look at the leaf shader. You must have green in the Translucency channel. Change the Translucency to either black or a much darker (less translucency effect) or a much less saturated(if you don't want the shadows as black) color.

Hope this helps.

Indeed it did!  Thank you...  

The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' (I found it!) but 'That's funny ...'
Isaac Asimov (1920 - 1992)