Honey Locust
Gleditsia triacanthos

ECOLOGY
Flowers provide nectar for insects. The pods are eaten by animals.

ETHNOBOTANY
The pulp on the inside of the pods is edible. Honey locusts produce a high quality, durable wood that polishes well, but the tree does not grow in sufficient numbers to support a bulk industry. However, a niche market exists for honey locust furniture.

NATURAL DISTRIBUTION
Native to the central part of North America.

TAXONOMY AND NAME
This plant is in the Fabaceae, the legume family. There are 13 species of Gleditsia native to the Americas and Asia.
The etymological root of the binomial name Gleditsia is named after Johann Gottlieb Gleditsch who was the 18th century director of the Berlin Botanic Gardens. Tricanthos is derived from the Greek tri 'three and acanthos 'spine' referring to the spines of this tree. The name of the selection “inermis” means unarmed, defenceless—referring to the thornless nature of that selection.

There are numerous selections, most of which are thornless (Gleditsia triacanthos inermis), though we think the thorns are one of the coolest things about this species.

'Beatrice' A cultivar that has been nearly or wholly unavailable in the plant trade since the 1980s. It was sourced from a then 50-year-old tree in Beatrice, Nebraska by the Inter-State Nursery of Hamburg, Iowa in 1955. This cultivar is shaped similarly to an American elm with a wide, spreading top and is also thornless and nearly pod free.

'Continental' The 'Continental' cultivar has especially large leaves of a darker blue-green shade during the summer. It is a large and vigorous selection with a narrow crown that is thornless and nearly seedless. It was introduced to plant commerce by Princeton Nursery of New Jersey in 1973 and patented in 1958.

'Elegantissima' Also known as 'Compacta', Gleditsia sinensis 'Inermis', 'Globe Honey Locust' and 'Bushy Honey Locust', this cultivar had become very rare by 1996. It is a bushy tree with smaller leaflets with slow growth, only reaching about 12 ft when 25 years old. It has a narrow vase shaped crown and is thornless. It is propagated on its own roots, from ground budding, and also top grafted. It was raised by the nurseryman Charles Breton of Orléans in France around 1880. It has, in some cases, reached large sizes.

'Emerald Kascade' This cultivar has a weeping form, with branches that cascade downward. Because it does not produce a leader it must be grafted onto a standard, an upright section of trunk, or be staked. It is reported to be both thornless and fruitless. The leaves are dark green in the summer and bright yellow in the autumn. It was introduced to the horticultural trade by the Duncan & Davies nursery in New Zealand in 1992. It is hardy to USDA zone 3. It is alternatively spelled 'Emerald Cascade' by some sources.

'Imperial' It is a popular cultivar that grows to only about 35 ft in height. It is of very regular growth habit with branches that emerge at right angles to the trunk and a symmetrical arrangement around it. It is noted for its rounded crown. Due to the lower emergence of main branches it requires significant amounts of pruning to be used as a street tree where clearance above vehicles is required. It is used where a somewhat smaller shade tree is required.

'Shademaster' This is a very popular cultivar of the honey locust. Trees have a straight trunk and branches that grow outward and then curve upward to create a symmetrical crown. Very often, without trimming, they will have three or four leaders. At 15 years of age the top of the tree is relatively flat, creating a vase like shape. Compared with 'Skyline' it has a finer branch structure and wider angles where branches attach to the trunk. Sources disagree on the maximum height obtained by this cultivar, Perdue lists it as 45 ft while the University of Florida lists it as 50 to 70 ft. Trees will produces a few pods when mature and are thornless with dark green foliage in summer.

'Skyline' This is a very common cultivar that has a more pyramidal or slightly squared shape to its canopy. Full grown trees may reach a height of 50 ft or more. Of five standard cultivars including 'Imperial, 'Moraine', 'Shademaster', and 'Sunburst' it showed the greatest height after 15 years of growth. Trees tend to have one or two larger leaders and evenly spaced branches with somewhat narrower crotch angles. Trees can be trimmed to develop one strong central leader with little pruning, because of this lower branches can be removed without distoring the even shape of the crown. This habits make it appropriate as a street tree where lower branches must be removed. The leaflets have a redish to bronze tone when emerging and a dark green and leathery appearance for most of the season. It was introduced by the Cole Nursery in Painesville, Ohio in 1957.