These quick growing bushes become round thickets filled with thorns. The thorns ooze some toxins that get into what ever they scratch. Depending on the subspecies, it can be itchy, or neurotoxin or acidic. When the Thorn Roll reaches some maturity and it runs out of water, its shallow roots begin to shrivel up. The wind will free it from the soil. The bush tumbles across The Wastes spreading seeds.
"Tumbling dang danger" the old old prospector said.