1. Robinia pseudoacacia L.

    1. Black locust is a rapidly growing, deciduous tree that is native to North America. This member of the pea and bean family (Leguminosae) was first introduced to Europe from North America at the beginning of the 17th century. Its hanging clusters of scented, white flowers are a common sight in streets and parks in England in June and July. Black locust, especially in its many named cultivars, has become a much-loved ornamental in western European gardens. Its cultivars include pink-flowered and metallic, yellowish-green leafleted forms. Despite its popularity as an ornamental, it can become invasive due to its prolific seed production, and it also spreads aggressively by suckering from the roots.

[KSP]

Kew Species Profiles

General Description
A rapidly growing tree native to southeastern North America, black locust is loved by many as an elegant ornamental of parks and city streets.

Black locust is a rapidly growing, deciduous tree that is native to North America. This member of the pea and bean family (Leguminosae) was first introduced to Europe from North America at the beginning of the 17th century. Its hanging clusters of scented, white flowers are a common sight in streets and parks in England in June and July. Black locust, especially in its many named cultivars, has become a much-loved ornamental in western European gardens. Its cultivars include pink-flowered and metallic, yellowish-green leafleted forms. Despite its popularity as an ornamental, it can become invasive due to its prolific seed production, and it also spreads aggressively by suckering from the roots.

Species Profile

Geography and distribution

Black locust is native to southeastern North America and has also been introduced to Britain and parts of Western Europe, as far north as the Netherlands. It is widely cultivated elsewhere and can become invasive.

Description

Overview: Black locust is a tree up to 25 m high with a rounded crown and a trunk up to 1 m in diameter. Its grey-brown bark is rough and deeply furrowed. Black locust trees often produce suckers (shoots which come out of the ground some distance from the main trunk). The sucker shoots and young branches are usually armed with spines (formed from pairs of stipules, leaf-like structures on the base of the leaf, that become woody and sharp with age).

Leaves: The leaves are pinnate (divided into a central axis bearing leaflets) with 3–11 pairs of oval leaflets and one extra terminal leaflet. At maturity the leaflets are almost hairless.

Flowers: The scented flowers are 15–20 mm long. The calyx (outer whorl of floral organs) is reddish-purple, and the petals are white (the standard petal having a basal yellow blotch). The stalked flowers are clustered into showy, hanging racemes.

Fruits:The fruits are linear-oblong, hairless pods, with the upper suture (margin) slightly winged, and there are 4–10 seeds per pod.

Naming of the genus

The genus Robiniawas named by the Swedish botanist Carl Linnaeus in honour of the French botanist Jean Robin (1550–1662) and his son Vespasien Robin (1579–1662), royal gardeners to Henry IV of France. It was Vespasien who first planted a specimen of R. pseudoacaciain the Jardin des Plantes in Paris in 1601, and the species was introduced to England soon after. A specimen of R. pseudoacaciaplanted in 1762 is one of the oldest trees currently standing in the Royal Botanic Gardens, Kew.

Threats and conservation

Black locust is a common, widespread species and is not considered to be threatened.

Uses

Robinia pseudoacaciais cultivated widely as an ornamental. Numerous cultivars have been bred in Europe, including some elegant leaf and flower colour forms, and a number of hybrids exist. In France, trees are sometimes heavily infested with mistletoe ( Viscum album), which is harvested for medicinal and decorative uses.

In the 18th century, the decay-resistant wood of black locust was used for fence posts, floors and cart wheels. 

The flowers are a nectar source for bees and yield a high quality honey, which is gathered in Europe and North America. The fragrant flowers are also used in perfumery.

Black locust is also planted to control erosion and is used for soil enrichment (it is a nitrogen fixer, by means of bacteria inside special root nodules). 

Known hazards

Some parts of the plant are toxic, particularly the bark, and poisoning of humans and livestock has occasionally been reported. Buildings have been damaged as a result of large branches breaking off mature street trees. Its sharp thorns are also a hazard.

Millennium Seed Bank: Saving seeds

The Millennium Seed Bank Partnership aims to save plant life worldwide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.

Five collections of Robinia pseudoacacia seeds are held in Kew’s Millennium Seed Bank based at Wakehurst in West Sussex.

See Kew’s Seed Information Database for further information on Robinia pseudoacacia seeds

Cultivation

Black locust can be propagated by seed, root cuttings or sucker shoots. Some pruning of the shoots of young specimen trees in winter strengthens the following year’s growth and reduces wind damage of the somewhat brittle branches. To avoid the loss of main branches, older trees should be kept to a single leader until seven or eight metres high, so that a strong, straight trunk is formed.

This species at Kew

A specimen of black locust planted in 1762 can be seen growing adjacent to the wisteria arch and Secluded Garden, near Elizabeth Gate at Kew.

Pressed and dried specimens of Robinia pseudoacaciaare held in Kew’s Herbarium, where they are available to researchers by appointment.

Specimens of the wood and bark of black locust are held in Kew’s Economic Botany Collection in the Sir Joseph Banks Building, where they are available to researchers by appointment.

Kew's 'Old Lions'

Kew’s ‘Old Lions’ are some of the few remaining trees with the oldest actual known planting date of 1762. They comprise: Ginkgo biloba (maidenhair tree), Styphnolobium japonicum (pagoda tree) and Platanus orientalis (oriental plane) to the west of the Princess of Wales Conservatory; Robinia pseudoacacia (black locust) on the lawn to the front of the Orangery; and Zelkova carpinifolia (Caucasian elm) situated in the Herbarium paddock.

Some of these trees were brought from a neighbouring estate at Whitton which belonged to the Duke of Argyll (the uncle of Lord Bute, the botanical advisor to Princess Augusta). They became part of a new five-acre arboretum, laid out by William Aiton, which sat next to the Orangery.

Now, 250 years after these trees were planted, Kew is celebrating the ‘Old Lions’, which can be seen in all their splendour, still growing in the Gardens.

Distribution
USA
Ecology
Dry, sandy and rocky habitats; scrub and woodland margins and roadsides; widely cultivated as an ornamental tree in streets and parks.
Conservation
Least Concern (LC) according to IUCN Red List criteria.
Hazards

See below.

[KSP]
Use
Ornamental, timber, soil enrichment, bee forage for honey production, perfume.

Images

Distribution

Found In:

Alabama, Arizona, Georgia, Illinois, Pennsylvania, Tennessee

Introduced Into:

Albania, Algeria, Argentina Northeast, Austria, Baltic States, Belarus, Belgium, Bulgaria, Canary Is., Cape Provinces, Central European Rus, Chile Central, China North-Central, China South-Central, China Southeast, Czechoslovakia, East Aegean Is., East European Russia, Easter Is., France, Free State, Germany, Great Britain, Greece, Hungary, India, Inner Mongolia, Iraq, Italy, Kazakhstan, Khabarovsk, Kirgizstan, Korea, Kriti, Krym, Kuril Is., KwaZulu-Natal, Libya, Madeira, Manchuria, Mexico Northwest, Morocco, Netherlands, New Mexico, New Zealand North, New Zealand South, North Caucasus, Northern Provinces, Pakistan, Palestine, Primorye, Qinghai, Romania, Réunion, Sakhalin, Sardegna, Sicilia, South European Russi, Spain, Switzerland, Tadzhikistan, Taiwan, Transcaucasus, Turkey, Turkey-in-Europe, Turkmenistan, Ukraine, Uruguay, Uzbekistan, West Himalaya, Xinjiang, Yugoslavia

Common Names

English
Black locust

Robinia pseudoacacia L. appears in other Kew resources:

First published in Sp. Pl.: 722 (1753)

Accepted in:

  • [1] Bailey, C. & al. (2015) Guide to the Vascular Plants of Tennessee . University of Tennessee press.
  • [4] Dimpoulos, P., Raus, T., Bergmeier, E., Constantinidis, T., Iatrou, G., Kokkini, S., Strid, A., & Tzanoudakis, D. (2013) Vascular plants of Greece. An annotated checklist . Botanic gardens and botanical museum Berlin-Dahlem, Berlin and Hellenic botanical
  • [6] (2013) Botanical Sciences 91: 461-475
  • [10] (2012) Flora Neomexicana , ed. 2, 1: 1-599. Range Science Herbarium, Las Cruces, New Mexico.
  • [11] (2012) Journal of Economic and Taxonomic Botany 36: 33-45
  • [12] (2012) Index synonymique de la flore d'Afrique du nord 4: 1-431. Éditions des conservatoire et jardin botaniques, Genève.
  • [13] (2012) Phytologia Balcanica 18: 333-373
  • [14] (2011) Saussurea; Travaux de la Société Botanique de Genève 41: 131-170
  • [15] Kral, R., Diamond, A.R., Ginzbarg, S.L., Hansen, C.J., Haynes, R.R., Keener, B.R., Lelong, M.G., Spaulding, D.D. & Woods, M. (2011) Annotated checklist of the vascular plants of Alabama . Botanical reseach institute of Texas.
  • [17] (2011) Dumortiera 99: 1-10
  • [19] Flora of China Editorial Committee (2010) Flora of China 10: 1-642. Science Press (Beijing) & Missouri Botanical Garden Press (St. Louis).
  • [21] (2010) Willdenowia 40: 189-204
  • [24] (2009) Le Journal de Botanique de la Société Botanique de France 46-47: 1-136
  • [26] (2008) Monographs in Systematic Botany from the Missouri Botanical Garden 107: 1-3348. Missouri Botanical Garden.
  • [29] (2003) Strelitzia 14: 1-1231. National Botanical Institute, Pretoria.
  • [30] Kumar, S. & Sane, P.V. (2003) Legumes of South Asia. A Checklist . Royal Botanic Gardens, Kew.
  • [32] Isely, D. (1998) Native and Naturalized Leguminosae (Fabaceae) of the United States . Monte L. Bean Life Science Museum. Brigham Young University, Provo, Utah.
  • [33] Lee, W.T. (1996) Lineamenta Florae Koreae . Soul T'ukpyolsi: Ak'ademi Sojok.
  • [34] Yakovlev, G.P., Sytin, A.K. & Roskov, Y.R. (1996) Legumes of Northern Eurasia. A checklist . Royal Botanic Gardens, Kew.
  • [38] (1991) Palmarum Hortus Francofurtensis 3: 1-108
  • [40] (1990) Flore des Mascareignes 80: 1-235. IRD Éditions, MSIRI, RBG-Kew, Paris.
  • [43] (1989) Med-checklist 4: 1-458. Conservatoire et Jardin Botaniques de la Ville de Genève.
  • [45] (1988) Flora of New Zealand 4: 1-1365. Botany division, D.S.I.R., Christchurch.
  • [49] (1974) Flora of Iraq 3: 1-662. Ministry of Agriculture & Agrarian Reform, Baghdad.
  • [50] Tutin, T.G. & al. (eds.) (1968) Flora Europaea 2: 1-469. Cambridge University Press.

Literature

  • [2] Bailey, C. & al. (2015) Guide to the Vascular Plants of Tennessee . University of Tennessee press.
  • [3] Mohlenbrock, R.H. (2014) Vascular Flora of Illinois. A Field Guide , ed. 4: 1-536. Southern Illinois University Press, Carbondale.
  • [5] Dimpoulos, P., Raus, T., Bergmeier, E., Constantinidis, T., Iatrou, G., Kokkini, S., Strid, A., & Tzanoudakis, D. (2013) Vascular plants of Greece. An annotated checklist . Botanic gardens and botanical museum Berlin-Dahlem, Berlin and Hellenic botanical
  • [7] (2012) Flora Neomexicana , ed. 2, 1: 1-599. Range Science Herbarium, Las Cruces, New Mexico.
  • [8] (2012) Index synonymique de la flore d'Afrique du nord 4: 1-431. Éditions des conservatoire et jardin botaniques, Genève.
  • [9] (2012) Journal of Economic and Taxonomic Botany 36: 33-45
  • [16] Kral, R., Diamond, A.R., Ginzbarg, S.L., Hansen, C.J., Haynes, R.R., Keener, B.R., Lelong, M.G., Spaulding, D.D. & Woods, M. (2011) Annotated checklist of the vascular plants of Alabama . Botanical reseach institute of Texas.
  • [18] (2010) Willdenowia 40: 189-204
  • [20] Flora of China Editorial Committee (2010) Flora of China 10: 1-642. Science Press (Beijing) & Missouri Botanical Garden Press (St. Louis).
  • [22] Veitch, N. C., Elliott, P. C., Kite, G. C. & Lewis, G. P. (2010). Flavonoid glycosides of the black locust tree, Robinia pseudoacacia (Leguminosae). Phytochemistry 71: 479–486.
  • [23] (2009) Le Journal de Botanique de la Société Botanique de France 46-47: 1-136
  • [25] (2008) Monographs in Systematic Botany from the Missouri Botanical Garden 107: 1-3348. Missouri Botanical Garden.
  • [27] Sternberg, G. & Wilson, J. (2004). Native Trees for North American Landscapes. Timber Press, Portland, Oregon.
  • [28] (2003) Strelitzia 14: 1-1231. National Botanical Institute, Pretoria.
  • [31] Kumar, S. & Sane, P.V. (2003) Legumes of South Asia. A Checklist . Royal Botanic Gardens, Kew.
  • [35] Yakovlev, G.P., Sytin, A.K. & Roskov, Y.R. (1996) Legumes of Northern Eurasia. A checklist . Royal Botanic Gardens, Kew.
  • [36] Lavin, M. & Sousa M. (1995). Phylogenetic systematics and biogeography of the tribe Robinieae (Leguminosae). Systematic Botany Monographs 45: 1–165.
  • [37] (1991) Palmarum Hortus Francofurtensis 3: 1-108
  • [39] (1990) Flore des Mascareignes 80: 1-235. IRD Éditions, MSIRI, RBG-Kew, Paris.
  • [41] (1989) Med-checklist 4: 1-458. Conservatoire et Jardin Botaniques de la Ville de Genève.
  • [42] Blamey, M. & Grey-Wilson, C. (1989). The Illustrated Flora of Britain and Northern Europe. Hodder & Stoughton, London.
  • [44] (1988) Flora of New Zealand 4: 1-1365. Botany division, D.S.I.R., Christchurch.
  • [46] Isley, D. & Peabody, F. J. (1984). Robinia (Leguminosae: Papilionoideae). Castanea 49: 187–202.
  • [47] Bean, W. J. (1980). Trees and Shrubs Hardy in the British Isles, Volume IV (Ri-Z). John Murray, London.
  • [48] (1974) Flora of Iraq 3: 1-662. Ministry of Agriculture & Agrarian Reform, Baghdad.
  • [51] Tutin, T.G. & al. (eds.) (1968) Flora Europaea 2: 1-469. Cambridge University Press.

Sources

Kew Species Profiles
Kew Species Profiles
[A] http://creativecommons.org/licenses/by-nc-sa/3.0
[B]

World Checklist of Selected Plant Families
World Checklist of Selected Plant Families(2016). Published on the Internet http://apps.kew.org/wcsp/
[C] See http://kew.org/about-kew/website-information/legal-notices/index.htm You may use data on these Terms and Conditions and on further condition that: The data is not used for commercial purposes; You may copy and retain data solely for scholarly, educational or research purposes; You may not publish our data, except for small extracts provided for illustrative purposes and duly acknowledged; You acknowledge the source of the data by the words "With the permission of the Trustees of the Royal Botanic Gardens, Kew" in a position which is reasonably prominent in view of your use of the data; Any other use of data or any other content from this website may only be made with our prior written agreement. http://creativecommons.org/licenses/by-nc-sa/3.0
[D] © Copyright 2016 International Plant Names Index and World Checkist of Selected Plant Families. https://creativecommons.org/licenses/by/3.0