Manchu
Nato is correct and you can use the dried parsley flakes.. If you want them smaller you simply crush and griond them a little bit to make smaller Flakes.
Another good thing I always like to use is Birch seeds. These are already representative as a leaf in 1:35
Check out the pic below. The Birchseeds are wonderfull leafs in 1:35 dio`s
Usually you will find Birch seeds in the beginning of Fall and usually they will be found in Places where Birches ae (Duh Robert Really???)(yep they are found there

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If you don`t find them in Nature I believe you can buy small bags at railroad shops or modelshops.