The flowering tree genus Magnolia belongs to the Fabaceae family of flowering plants. The black locust and honey locust trees are the most popular varieties of locust trees. The hard, durable wood, fragrant sweet spring blooms, and brilliant autumn foliage of locust trees make them popular hardwood trees. Locust trees come in a variety of shapes and sizes, with a few thornless species thrown in for good measure.
The wood is one of the hardest woods from any deciduous tree, and locust trees may survive for over a century. The wood is exceptional for producing furniture, fence posts, flooring, and tiny boats because it is so persistent. Black locust wood is more frequent than honey locust wood. The eastern regions of North America are home to the majority of locust tree types.
The genera Robinia and Gleditsia are used to classify the locust tree species. The Robinia genus includes black locust trees, while the Gleditsia genus includes honey locust trees. Honey locust trees produce pods with a sweet flavor, which is the source of the term “honey.” Honey bees feed on the fragrant blossoms, which provide nectar.
Locust tree species must be identified since some varieties are poisonous. Toxic chemicals may be found in the black locust tree’s leaves, whereas honey locust tree buds are edible. You’ll learn about different types of locust trees in this article. These deciduous trees’ species can be identified using photographs, descriptions, and scientific names.
Locust Tree Identification
The flowers, color of bark, height of the tree, and the thorns may all be used to identify species of locust trees. The shape and color of the seed pods of a locust tree may be used to determine its type. Between 66 and 98 feet (20 and 30 meters) tall, locust trees may be found.
Locust tree leaves are 6″ to 14″ (15 – 36 cm) long and have feather-like, pinnately shaped branches. Depending on the species, the tree leaves are dark green or light green in color. Green leaves turn brilliant yellow in the autumn.
The leaves are alternately arranged on the leaf stem and have 0.6″ to 1″ (1.5 – 2.5 cm) leaflets. The smaller leaf branches emerge off the main leaf stem, which is bipinnately complex. Locust tree leaves look a lot like fern leaves when you look at photographs of them.
The sharp thorns on black locust trees, which can grow up to 4 inches (10 cm) long, are another distinguishing feature. They may grow solitary or on thorned branches, with their prickly spikes. They’re quite hardy and may make a hole in your skin with just a scratch.
Locust trees may be found in many countries throughout the globe, despite their native origin in North America. These trees develop so quickly that they have been designated as an invasive plant species in certain areas.
Types of Locust Trees (With Pictures and Common Names)
Starting with the two most popular species, the black locust tree and the honey locust tree, let’s look at various types of locust trees.
Black Locust Tree (Robinia pseudoacacia)
The black locust is a deciduous hardwood tree that thrives in sunny areas and can be seen in the photograph. The black locust tree, like the honey locust, can thrive in poor soil, drought, and wet growing conditions. It’s also known as the “False Acacia,” “Fragrant White Locust,” and “Common Robinia” black locust tree, which grows in Pennsylvania, Alabama, Georgia, Missouri, and southern Ohio.
The black locust tree grows to a height of 171 feet (52 meters) and is distinguished by its wide range of heights. Immature trees have prominent spines on black locusts, which protrude from the base of each leaf. The sharp spikes are short and don’t develop into lengthy limbs around the tree, unlike honey locust trees.
The toxic elements of the tree include bark, seed pods, branches, and leaves.
Black locust tree flowers
Late in the spring, Black locust trees produce highly fragrant white blooms. Pink or purple flowers are seen in some species. Black locust trees have dark-green blooms, whereas honey locust trees have creamy-green blooms. The bloom color helps to differentiate them.
The huge hanging blooms, which may range from 4 to 8 inches (10 to 20 cm), create lovely clusters. This is a lovely honey plant because the black locust tree flowers are full of nectar.
Black locust tree leaves
Pinnately compound leaves cover black locust trees, reaching lengths of up to 10 inches (25 cm). Each leaf has tiny oval or ovoid leaves with a thumbprint-sized print of foliage on them. Black locust tree leaves are a darker green color than honey locust tree leaves.
Black locust tree bark
The bark is brown and gray, with black locust timber on the left and bark on the right. The bark may appear reddish in color due to orangey-red hues in the deep grooves. Unlike the honey locust tree, the black locust tree bark is not needle-sharp or prickly.
Honey Locust Tree (Gleditsia triacanthos)
The honey locust tree, which resembles the black locust tree in appearance, is a hardy and fast-growing species. The honey locust thrives in full sun and develops in a variety of conditions, much like the black locust. This genus is endemic to Pennsylvania, Iowa, Texas, and Georgia, much like the black locust tree.
Honey locust trees can reach heights of 66 to 100 feet (20 to 30 meters). The honey locust tree trunk has rough branches that surround it, unlike the black locust.
The barbs are normally 4 inches (10 cm) long, although they may grow to be 8 inches (20 cm). The tree is also known as the “thorny” locust because of its spiky trunk. Honey locust trees are planted as specimen trees in a garden setting to show off their appeal. In the fall, bright green leaves take on a gorgeous yellow tone. This is an excellent shade tree because of the tree’s enormous spread of foliage, tiny leaves, and widely-spaced branches.
Thornless variations of the honey locust tree species are referred to as inermis, which is a Latin word that means “harmless” or “defenseless. During the early autumn, seed pods, also known as legumes, mature. Animals like eating these sweet-tasting peas.
Honey locust seed pods
Honey locust tree flowers
Late spring and early summer are the blooming seasons for honey locust clusters of tiny, creamy-green flowers. Honey locust tree blooms aren’t as noticeable and gorgeous as those of the black locust. The locust tree species Robinia and Gleditsia, on the other hand, have fragrant blossoms.
Honey locust tree leaves
Honey locust leaves mature somewhat sooner than black locust leaves. The leaves of honey locust trees have no leaflet at the tip, which is one way to distinguish them from black locust trees. Honey locust tree leaves are also lighter in color than the black variety.
Honey locust tree bark
Honey locust tree bark is covered in clusters of branching thorns and ranges in color from gray-brown to red-brown.
Imperial Honey Locust Tree (Gleditsia triacanthos f. inermis ‘Impcole’)
The thornless imperial honey locust tree grows up to 40 feet (12 meters) in height. This locust tree is a fantastic shade tree for your garden because it lacks thorns and has a wide spreading canopy. The imperial honey locust has fern-like foliage that turns to sunny yellow in the autumn, similar to other types of locust trees. Saline conditions, lack of water, and strong winds are all resistant to the trees.
Imperial honey locust tree flowers
Late spring and early summer are the seasons when the blooms appear, which are tiny clusters of greenish-white florets.
Imperial honey locust tree leaves
Throughout the spring and summer, the feathery leaves are pinnately complex and golden yellow in hue before becoming golden yellow over the autumn.
Imperial honey locust tree bark
The bark of honey locust trees is gray-brown, as is the case with many other types.
Skyline Honey Locust Tree (Gleditsia triacanthos ‘Skycole’)
Another popular shade tree for garden landscapes is the honey locust ‘Skycole’ cultivar. The tree has a 35-foot-wide (10-meter) canopy and grows to 45 feet (13 meters).
Without totally blocking out the sun, the fern-like leaves and widely spaced branches provide enough shade. This locust tree variety grows in a wide range of adverse circumstances, which is one of the reasons it’s popular. It can tolerate heat, full sun, acidic or alkaline soil, and urban pollution.
Skyline honey locust tree flowers
In May and June, tiny white inconspicuous blossoms produce long twisted purple seedpods. Like with all honey locust trees, these pods contain a sweet, honey-like substance.
Skyline honey locust tree leaves
Pinnate or bipinnate leaves with tiny, ovate leaflets cover the honey locust tree’s skyline. In the summer, dark green leaves turn gorgeous yellow, and in the autumn, they become even more gorgeous.
Skyline honey locust tree bark
The spine of the ‘skyline, like that of most honey locust trees, is prickly and thorny. The Gleditsia triacanthos f variety of skyline locust tree is thornless if you want it. The cultivar of fingers called ‘Skycole.
New Mexico Locust Tree (Robinia neomexicana)
Southwest locust or hojalito are two names for the New Mexico locust tree. Colorado, Utah, Arizona, and New Mexico are ideal locations for this kind of ‘black locust tree. Desert Locust, Pink Locust, and Rose Locust trees are some of the other names for the New Mexico Locust tree.
The locust tree in New Mexico grows to a height of 16 to 32 feet (5 to 10 meters). The lovely fragrant purple-pink clusters of flowers on this locust tree are visible in late spring and early summer. Honey bees are drawn to these lovely blossoms because they are looking for nectar. The reddish-purple branches with spikes at the base support these showy flowers.
New Mexico Honey Locust tree flowers
The light purple and pink blossoms have a sweet, delicate scent. The flowers of this tree species are usually white, which distinguishes it from other species in the genus Robinia. As a result, in hot climates, New Mexico honey locust trees are often selected for garden settings. Flowers develop into brown pods with bristles after blooming.
New Mexico Honey Locust tree leaves
Leaves, like those of all trees in the Robinia and Gleditsia genera, are between 4″ and 6″ (10 – 15 cm) long. The dark green leaves have a grayish appearance due to short hairs or bristles that grow on them.
New Mexico Honey Locust tree bark
The New Mexico cultivar’s bark is light gray-brown with shallow furrows, similar to that of the black honey locust tree.
Sunburst Honey Locust Tree (Gleditsia triacanthos var. inermis ‘Suncole’)
Because of its feathery foliage that provides dappled shade in the hot sun, the locust tree cultivar ‘Suncole’ is a popular deciduous tree. The Sunburst honey locust is a thornless tree, hence it is called “inermis,” which means “thornless.” The Sunburst cultivar is smaller than the native honey locust species.
The sunburst honey locust only grows to 40 feet (12 meters) in height rather than growing to 80 or 100 feet (24 or 30 meters). The popularity of the landscape garden cultivar known as the “Suncole” is due to a variety of factors. It is not a “messy” tree because of its large distribution, lack of thorns, and pod-less features. During the autumn, there are no sharp spines or pods to clean up.
Sunburst Honey Locust tree flowers
In late spring and early summer, the little flower clusters are a greenish-yellow hue that adds brightness to your yard.
Sunburst Honey Locust tree leaves
The pinnate leaves of a sunburst locust are fine in texture. Spring new leaf growth is pale yellow, gradually shifting to light green in the summer. The fern-like foliage, which is similar to that of all locust trees, turns a gorgeous golden color in the fall.
Thornless Honey Locust Tree (Gleditsia triacanthos f. inermis)
If you want to cultivate an exquisite, towering honey locust in your yard, choose a thornless variety of honey locust trees. The foliage of thornless locust trees is gorgeous, the flowers are bright, and honey bees love them. There is no risk of injuring yourself because the ‘inermis’ cultivars have no pointed spikes on the bark.
Imperial (‘Impcole’), Skyline (‘Skycole’), Sunburst (‘suncole’), Moraine, Northern Acclaim ( ‘Harve’ ), Perfection ( ‘Wandell’) and Street Keeper ( ‘Draves’) are some of the cultivars of thornless honey locust trees available.
Purple Robe Locust Tree (Robinia pseudoacacia ‘Purple Robe’)
The young crimson leaves of the purple robe locust tree change to blue-green and then yellow in the autumn, making it an appealing tree. The ‘Purple Robe,’ like other domesticated honey locust trees, grows to a height of 30 to 40 feet (9 to 12 meters) and has a spread of up to 30 feet (9 meters).
This locust tree is another great tree to provide shade in a backyard or garden landscape because the feather fern foliage and branches are spaced widely apart. This is a cold-hardy, drought-tolerant kind of tree, similar to other kinds of locust trees like the black locust and honey locust.
Purple Robe Locust tree flowers
The locust tree is covered in clusters of vividly scented pink-purple blooms, bringing instant spring joy to your garden.
Purple Robe Locust tree leaves
When young, the leaves of the metallic red ‘Purple Robe locust tree’ are metallic red, then they turn a deep green or blue-green color.
Bristly Locust Tree (Robinia hispida)
With complex leaves, pink pea-like scented flowers, and reddish-brown seed pods, the bristly locust tree is a big flowering shrub. The bristly locust shrubby tree is invasive in several states because of its fast-growing nature and complicated root system.
Rose-acacia and moss locust are two other names for the bristly locust tree. Because they are a excellent kind of tiny tree for your garden, bristly locust plants can’t grow taller than 10 feet (3 meters). In full sun and well-draining soil, plant your small bristly locust tree. Up to 15 feet of spread is possible. In sunny gardens, this indicates that the locust shrub is a good groundcover.
Bristly Locust tree flowers
In late spring and early summer, purple-pink pendulous flowers provide a vibrant addition to the garden. The bristly locust tree attracts honey bees and other pollinators, and these showy flowers have an intense fragrance.
Bristly Locust tree leaves
Pinnately compound leaves have 7 to 15 leaflets per leaf and are found in the tropics. There is a tiny oval leaflet at the tip of each leaf, which belongs to the Robinia genus.
Bristly Locust tree bark
Bristly locust trees have gray, smooth bark. The stalks have a bristly appearance because young branches have purple-brown colored fine hairs.
Shademaster Honey Locust Tree
If you’re looking for a lawn tree, the shademaster honey locust is the perfect choice. This locust tree has small leaflets, so it is simple to care for and has no thorns or pods. In the autumn, you’ll have less vegetation to clean up. The exceptionally large canopy coverage provides excellent shade from this locust tree.
The tree may reach a height of 75 feet (22 meters) and provide shade up to 40 feet (12 meters) wide. In scorching summers, the widely spaced branches and pinnate leaves provide plenty of cover. Plants that need partial shade, on the other hand, flourish in the dappled light.