DragonflyTV . Podcast - Cactus | PBS KIDS GO!

Source : http://pbskids.org/dragonflytv/show/cactus.html...

We're Mark and Alex, and we're junior docents at the Arizona - Sonora Desert Museum. We do presentations for museum visitors about the plants and animals you can see here, especially the saguaro cactus. One visitor asked a question about the holes that are visible in the arms of the cactus: Do the holes in a saguaro cactus always face the same direction?