Free images results:

Thistly pictures, stock photos and images


Thistle Stock Photo
Author: Mkartal

Also, here are some commercial RF-licensed images that match your search criteria:  
Cactuses Royalty Free Stock Photography
Author: Sarkao
Cactus Stock Photos
Author: Sarkao
Snail; Stock Image
Author: Tihov
Cactus Stock Image
Author: Alon-o