''Gleditsia'' (honey locust) is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

s in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Fabaceae, subfamily Caesalpinioideae,

native Native may refer to: People * Jus soli, citizenship by right of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Native Americans (disambiguation) In arts and entert ...

to North America and Asia. The Latin name commemorates

Johann Gottlieb Gleditsch Johann Gottlieb Gleditsch (5 February 1714, in Leipzig – 5 October 1786, in Berlin) was a German physician and botanist known for pioneer investigations of plant sexuality and reproduction. Biography He studied medicine and other subjects a ...

, director of the Berlin Botanical Garden, who died in 1786.

Species

There are 12 species: *'' Gleditsia amorphoides'' (Griseb.) Taubert *'' Gleditsia aquatica'' Marshall – water locust or swamp locust *'' Gleditsia assamica'' Bor *'' Gleditsia australis'' F. B. Forbes & Hemsley *''

Gleditsia caspica ''Gleditsia caspica'', the Caspian locust or Persian honeylocust, is a species of ''Gleditsia'' native to western Asia, in the Caucasus region of Azerbaijan and northern Iran, close to the Caspian Sea.Huxley, A., ed. (1992). ''New RHS Dictionary ...

'' Desf. – Caspian locust or Persian honeylocust *'' Gleditsia fera'' (Lour.) Merr. *''

Gleditsia japonica ''Gleditsia japonica'', the Japanese locust, is a species of flowering plant in the family Fabaceae, native to the eastern Himalayas, central and southern China, Manchuria, Korea, and central and southern Japan. It is used as a street tree ...

'' Miq. – Japanese honey locust *'' Gleditsia medogensis'' Z.C.Ni *'' Gleditsia microphylla'' D.Gordon ex Y.T.Lee *'' Gleditsia rolfei'' S.Vidal *'' Gleditsia sinensis'' Lam. – Chinese honey locust *''

Gleditsia triacanthos The honey locust (''Gleditsia triacanthos''), also known as the thorny locust or thorny honeylocust, is a deciduous tree in the family Fabaceae, native to central North America where it is mostly found in the moist soil of river valleys. Honey ...

'' L. – thorny honey locust Hybrids * ''Gleditsia'' × ''texana'' Sarg. – Texas honey locust (=''G. aquatica'' × ''triacanthos)'' All the species are woody except for ''G. microphylla''. Their ability to fix nitrogen is debated; see .

Range and Taxonomy

''Gleditsia'' is found in East Asia, on the East Coast of the Americas, and in South America; small populations of certain species also exist around the Caspian Sea (''G. caspica'') and India (''G. assamica''). There are native species to all these regions. The theory is that ''Gleditsia'' originated in East Asia in the Eocene, crossed the land bridge across the North Pacific Ocean into North America, and then spread down to South America millions of years later. ''Gymnocladus'' is a sister genus of ''Gleditsia,'' and it too mimicked this dispersion pattern, except it came to the Americas much earlier. Though there are no extant European ''Gleditsia'' species, there are fossils found in Europe which could mean that the genus also crossed the North Atlantic land bridge. Certain ''Gleditsia'' species are in clades with species from other continents; an example is ''G. caspica'' (from the Caucusus), ''G. delavayi,'' and ''G. japonica'' (both from Asia), who are in a clade together. ''Gleditsia amorphoides'' is the most basal of the genus, most closely related to ''G. sinensis'' but not the North American species (''G. aquatica'' and ''G. triacanthos'').

Medicinal use

''Gleditsia sinensis'' is one of the 50 fundamental herbs used in

Chinese herbology Chinese herbology () is the theory of traditional Chinese herbal therapy, which accounts for the majority of treatments in traditional Chinese medicine (TCM). A ''Nature'' editorial described TCM as "fraught with pseudoscience", and said that t ...

, where it is called ''zào jiá'' ( 皂荚).

References

Bibliography

*Philips, Roger. (1979). ''Trees of North America and Europe'', Random House, Inc., New York . Fabaceae genera Caesalpinioideae {{Caesalpinioideae-stub