Honeylocust

Gleditsia triacanthos
Family: Fabaceae

Natural History
Foliage of honeylocust
Photo credit: Chris Evans, Illinois Wildlife Action Plan, Bugwood.org

The honeylocust is a long-lived legume species that can grow to be over 100 feet tall. The tree is unusual because it can have both pinnately compound and bipinnately compound leaves on the same tree. The fruits are large, flattened legumes that dry to be almost black. Perhaps the most striking features of the tree are the large, sharp thorns that can form clusters along the trunk and branches. The thorns presumably protect the young trees from grazing herbivores.

Habitat & Range

This pioneering species is regularly grows in overgrown fields and along fence lines and wood lot edges.  It is adapted to a variety of soils and can withstand flooding and drought but prefers moist, fertile soils. While it is found most often in central to midwestern US, it is distributed nationwide.

Wildlife Use

Honeylocust pods are eaten by a variety of wildlife including white-tailed  deer, opossum, squirrel, rabbits, quail, crows, and starling. Browsing and grazing animals also eat the soft bark of young trees in winter and shoots in the spring.  When growing in dense thickets, honeylocust provides cover for small animals and birds.

Human Use

The nearly nationwide range of honeylocust may be due to spread by Native Americans who used the dried seeds and pulp as a food and sweetener. Because honeylocust is hardy and fast growing, it is often used today as an ornamental or planted as erosion control.  The thorns found on the trunk of the species are a major drawback for urban settings, but horticulture industry has developed thornless and fruitless varieties for landscaping.   Because the dense, coarse-grained wood of the honeylocust is easily split and polishes nicely it is commonly used a timber for fence posts, furniture and pallets.


 

Identifying Characteristics

Size/Form: Grows 30 to 50 feet tall with an open crown and thick branched thorns.
Leaves: The leaves are pinnately or bi-pinnately compound, alternate, and deciduous. They have many leaflets and are 6-8 inches long. The leaves are shiny dark green in the growing season, but they turn yellow before they drop off in the fall.
Twigs: Honeylocust twigs grow in a zigzag pattern. Larger twigs typically have thorns with three points.
Bark: Blackish to grayish bark that develop smooth plate like patches as the tree matures. In a natural environment, the bark can often have clusters of large, sharp thorns like knitting needles.
Flowers: Greenish yellow, fragrant small numerous in hanging clusters.
Fruit: Long, twisted, flattened green pods form in late summer and turn dark brown as they ripen. They are usually 15-40 cm long and can have a sweet ripe smell once they fall to the ground.
Similar Trees on the Florida 4-H Forest Ecology Contest List:
Several other plants on our list also have alternate, pinnately-compound leaves.

 

Images

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