Free images results:

Cacti pictures, stock photos and images


Cactus Stock Photo
Author: Dkgilbey
Cactus 1 Royalty Free Stock Image
Author: Minthu
Look Way Up Stock Images
Author: Mlane
Thorns Stock Photo
Author: Photong

Also, here are some commercial RF-licensed images that match your search criteria:  
Cacti Stock Photography
Author: Sangiorzboy
Cacti Royalty Free Stock Photos
Author: Rgbe
Cacti Stock Image
Author: Davinci
Cacti Stock Photos
Author: Alexeys