Plant Badge: Heraldry for common Scots

[The Celtic Gypsy]

I have a question and would like some help. I have been making clan crest badges and am just about ready to launch a web site to sell them along with some other clan related items. I am also developing items as i get ideas or see something i can do. As I was working on the crest badges, it was brought up about the clan plant or the actual clan badge. I have the template for the badge/pin and I will be using botanical illustrations, as opposed to photos, for the badges. (A pin or button about 2.25 inched in diameter, metal shell, mylar covering,pin back). Now comes the hard part. I am having a hard time finding illustrations of the actual plant ie: the rock ivy or the Scottish Thistle, as listed at various sites. If I used an illustration of any thislte or ivy would it matter?