The Devil's walking stick is a thorny tree found across southeastern North America, Latin name Aralia spinosa. There is a good chance that if you live in eastern or Midwestern America, you are familiar with either it or the unrelated but quite similar prickly ash tree (a.k.a. Hercules' club). Devil's walking stick is comparatively limited in range, living from northern Florida to Virginia, and out as far as the eastern edge of Texas and central Arkansas to the west.
Devil's walking stick initially appears as little more than a stick or poll growing up from the forest floor, 7-10 cm in diameter and 2-3 meters of nothing but thorny bark. The top has a terminal bud that, once the tree reaches a height safe from browsing herbivores, will burst out into an umbrella of large, lacy compound leaves; mature trees will widen their trunks to 15–20 cm in diameter, and may reach 8 meters in height. In the late summer a large plume of small white flowers emerges above the crown of the tree, and in the fall small purplish-black berries appear -- they look quite a bit like pokeweed berries -- and the mature berries are edible.
The tall, thorn-encrusted trunk is most likely an adaptive trait to protect against megafauna -- mammoths, giant ground sloths, and other large but now extinct animals; their height is much greater than that needed to protect against deer and bear.
These trees appear in disturbed patches of forest or on the margins of woodland, looking for patches of unused sunlight; they often appear in clusters in these areas, and humans who have tried to clear back the trees tend to view them as very large weeds.
The young leaves can be eaten as a pot herb; don't try this if the leaves have developed prickly spines along the mid-ribs. The young berries are poisonous, but the mature berries can be used for flavoring (they were a favorite of the Iroquois), but may not be safe to eat in large amounts. They, like prickly ash, have been used to treat toothache due to their numbing properties; this is not recommended if you have access to modern medicine and dentistry.
Prickly Ash and devil's walking stick are frequently confused; they may both be referred to as Hercules' club or a toothache tree, although I would reserve those terms for the prickly ash. Prickly ash is much more likely to have a branching trunk, but the thorns are probably the best way to tell them apart; the prickly ash generally has wart-like stubs with a wicked, rose-like (but larger!) thorn atop the wart. The devil's walking stick has more traditional (large, sharp) thorns, often clustered in lines along oddly placed 'joints' on the trunk, interspersed with little acne-like lumps and leaf scars.