Types of Spiny Trees

Some species of mesquites have 2-inch-long spines.

Some species of mesquites have 2-inch-long spines.

If you’ve ever been surprised by the sting of a tree's spine, you may have wondered exactly why some species are covered with prickly spikes. Also known as armament, these poky protrusions evolved from immature branches and leaf parts that converged into sharp points over time, according to the University of Arizona’s Ecology and Evolutionary Biology Department. Spines and thorns dissuade hungry mammals from making a meal out of tree bark, helping trees survive (ref. 2). If you're planting a spiny tree in a high traffic area, take precautions to avoid unwanted pokes and pricks.


Several members of the Aralia genus sport spiny bark; these include the Japanese angelica (A. elata), a 35-foot-tall deciduous tree with rough, spiny gray bark. Hardy in U.S. Department of Agriculture plant hardiness zones 4 to 9, these low-canopied trees bloom with white spring flowers. The devil’s walking stick or prickly ash (A. spinosa) also has prickly bark. It tends to produce thick, spiny suckers and can grow to 35 feet tall. It’s also hardy in zones 4 to 9.


Prickly members of the Cercidium genus include the blue palo verde (C. floridum subsp. Floridum), which has large thorns on its exfoliating or smooth bark. This deciduous Southern California native tolerates drought and blooms with showy yellow flowers in spring. The little leaf palo verde (C. microphyllum), another California native, also has spines and yellow blooms, but its bark and foliage have a yellow-green cast. Both grow to 35 feet tall and are hardy in USDA zones 8 to 9.


Several members of the Crataegus genus have spines, such as the English hawthorn (C. laevigata), a deciduous tree that grows up to 25 feet tall and is hardy in USDA zones 4 to 8. It tolerates a range of site conditions and flowers with pink-white blossoms in spring, followed by abundant red fruits. Spiny cultivars include the "Crimson Cloud," prized for its red flowers, and the "Paul’s Scarlet," which blooms with showy double blossoms. Other spiny hawthorns include the "Carriere" (C. x lavallei “Carriere”), which has an open canopy; the "Toba" (C. X mordenensis “Toba”) which produces less abundant fruits than many other hawthorns; and the Washington (C. phaenopyrum), a white-blooming species. All grow up to 25 feet tall and are hardy in zones 4 to 8.


Several species and hybrids in the Ilex genus have spines, including the Chinese holly (I. cornuta), a thorny evergreen that grows up to 20 feet tall. Hardy in USDA zones 7 to 9, Chinese hollies bear abundant red berries in fall and winter that attract wildlife. American hollies (I. opaca) also produce red berries. These evergreens grow up to 50 feet tall and are hardy in zones 5 to 9. Other spiny hollies include the "Nellie Stevens" (I. x “Nellie Stevens”), which grows to 25 feet and is hardy in zones 7 to 9, and the "Wilsonii" (I. x. “Wilsonii”), a drought-tolerant tree that grows to 25 feet and is hardy in zones 7 to 10.

Other Spiny Trees

Other spiny species include the California nutmeg (Torreya californica), a 35-foot-tall evergreen that's hardy in USDA zones 7 to 10. This North American native has dense, glossy foliage. The Japan pepper (Zanthoxylum piperitum) has aromatic bark and fruit and an airy, open canopy. It grows to 25 feet tall and is hardy in zones 6 to 9. The wild plum (Prunus americana) is prized for its fragrant spring flowers. This deciduous tree is hardy in zones 3 to 8 and grows to 25 feet tall.

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