Forests make up half of Michigan's landscape (nearly 18 million acres). Michigan's timber industry and wildlife rely heavily on this forest vegetation. Recreational activities within these forested areas, like hunting and camping, also impact the state's economy. More than 100 different species of trees, including several species of thorn trees, grow in the state of Michigan.
Plant a young horsechestnut tree and watch the tree grow at a rate of 18 inches per year. At full maturity, a horsechestnut grows to a height of 60 feet and an approximate width of 50 feet. Horsechestnuts bear thorny fruit and require some shelter from the wind. The horsechestnut transfers well, but prefers full sun. Horsechestnuts have white flowers on the branch tips. When the flowers drop, the tips grow nuts and spiny thorns. The tree is messy and drops leaves, nuts and twigs frequently.
Look for mosses and lichens on the tree's trunk when identifying a Douglas hawthorn tree (also called black hawthorn). Found in Michigan and many western states, the Douglas hawthorn grows between three and 13 feet high as a large shrub or small tree. Recognizing this tree's risk of extinction in Michigan, the United States Forestry Service continues to work to strengthen the tree's foothold in this state. Long, straight thorns, approximately one inch long, are characteristic of this tree. The leaves are long and serrated at the tip. Black smooth fruit also grows on the Douglas hawthorn. This tree is hearty and strong and loves moist soil. Douglas hawthorn trees have even survived avalanches in Glacier National Park in Montana, according to the USDA Forest Service.
Identify a cockspur hawthorn by looking for a small ornamental tree with a flat top. This thorned tree has white flowers and red fruit. The cockspur hawthorn also produces an abundance of fall colors, with leaves turning red, orange, purple and yellow. Summer leaves are about three inches long and a dark, glossy green. The thorns stand out to the naked eye with a length of two inches. Each thorn curves downward on the lower half and resembles a rooster's or "cock's" curved spur. At maturity, these trees reach about 15 feet tall and 20 to 25 feet wide. The cockspur hawthorn grows slowly in the vertical direction but has a medium growth rate horizontally and spreads at the top. The tree develops a dense mass of twigs and thorns with age.