My bouquet was made of white roses (for TD), wheat, bells of Ireland (we got engaged in Belfast), and thistle (I graduated from a Scottish university and a number of my Scottish friends were there). It looked like so:
My bridesmaids had just sheaves of wheat, and the groomsmen's boutonnieres were little sprigs of wheat.
My Mom and MIL had corsages of white roses, my dad and FIL had boutonnieres of white roses and wheat.
P had a boutonniere of thistle, wheat and white rose.