Spikes are sharp-tipped barbs or thornlike appendages that develop on stems or branches of plants. These pointy growths help protect plants from wild animals and other ecological threats. Plants with spikes have numerous uses such as a deterrent for burglars when planted near windows and along fences. Spiky plants aid in the protection of crops and livestock. Types of plants that grow spikes come in a large variety of sizes, shapes and species.
Prickly pear (Opuntia humifusa) is a woody succulent cactus with a low-growing configuration. This 1-1/2-foot-tall plant develops spiky stems and thick-segmented pads. During May through July, showy yellow blossoms with a spiny centre flourish on the prickly pear. Crown of thorns (Euphorbia Milii) is a 1- to 3-foot-tall woody succulent shrub with a spread of 2 to 3 feet. This endemic Madagascar plant has stems covered in large, slender spikes. A flowering shrub, crown of thorns blooms throughout the year with orange, gold and yellow blossoms
Ocotillo (Fouquieria splendens) is an indigenous desert plant of the Southwest U.S. and Mexico. This woody plant has tall clusters of grey spike-wrapped stems that develop leaves from spring until summer after the rains end. In April and May, Ocotillo flourishes with bold red blossoms. Bougainvillea (Bougainvillea spectabilis) is a quick-growing flowering woody climbing vine native to South America. This spiky-stemmed plant has a length of 3 to 20 feet and a spread of 6 to 8 feet. Bougainvillea is a drought-tolerant plant that thrives in full to light sun and well-draining soils.
Texas bullnettle (Cnidoscolus texanus) is a member of the Euphorbiaceae plant family. This 1- to 3-foot-tall herbaceous plant has an upright formation and develops spiky stems. The foliage of this Texas native has a medium green tone and is shrouded with stiff stinging hairs. April through September, the Texas bullnettle produces showy white flowers. Mile-a-minute vine (Polygonum perfoliatum) is a annual herbaceous vine with a fast rate of growth of up to 6 inches a day, according to the University of Maine. This invasive vine originates from Asia and has a trailing form with pale green foliage. The stems of the mile-a-minute vine form ridged small spikes with a downward arch.
Hawaii goosefoot (Chenopodium oahuense) is a woody shrub native to Hawaii. This plant comes in a wide range of sizes from 2 to 30 feet in height. The flowers of the Hawaii goosefoot grow in clusters of small greenish-white blossoms that form on spiky stems. Hawaii goosefoot is a year-round blooming shrub. Wintergreen barberry (Barberis julianae) is a flowering broadleafed evergreen shrub native to China. This Berberidaceae family plant grows to heights of 4 to 6 feet tall with a 6- to 8-foot-wide spread. Wintergreen barberry develops has 3-inch-long narrow leaves that form on spiky woody stems.