Here are some plants that I've used to make miniatures:
- Capsicum seeds when dried make perfect potato chips.
- Grape pips when dried look like little pears for a fruit bowl or food sack.
- Grape stems can be dried and when foliage is glued on can be used for trees.
- Lichen can be separated into tiny bits and glued on roof tiles in places to make a dolls house roof look old. Or it can be left in clumps and used as bushes in a garden, especially if sprayed green.
- Acorn caps when sandpapered smooth make nice wooden bowls.
- Coriander seeds look like 1:12 scale nuts.
- Walnut shells make tiny cradles. Or I have used them sliced across as wooden platters, as in the photo.
- Strips of bark look great as the outer covering of a woodland cottage or tree stump house.
- Thin tree branches, sliced into rounds, make stepping stones in a garden scene.
I'm sure you have more ideas for using plants as minis. Let me know!