Free images results:

Roots pictures, stock photos and images


Tree Trunks Stock Images
Author: Lydia
Old tree Royalty Free Stock Photography
Author: Razvanjp
Hyacinth Royalty Free Stock Photos
Author: Rbouwman

Also, here are some commercial RF-licensed images that match your search criteria:  
Tree roots Stock Photos
Author: Sherez
Tree roots Royalty Free Stock Photo
Author: Julkab
Roots Stock Image
Author: Mikeexpert