Start a consultation

Support Tree TSAR: Sponsorship Opportunities

Robinia pseudoacacia L.

Black locust

Synonyms
  • Aeschynomene pseudoacacia Roxb. ex DC.
  • Derris robusta var. assamica Thoth.
  • Pseudacacia odorata Moench
  • Pseudacacia vulgaris Tourn. ex Greene
  • Pseudo-acacia vulgaris Medik.
  • Robinia acacia L.
  • Robinia amorphifolia K.Koch
  • Robinia angulata K.Koch
  • Robinia aurea K.Koch
  • Robinia bessoniana K.Koch
  • Robinia bullata K.Koch
  • Robinia camusetii Leroy ex K.Koch
  • Robinia coluteoides K.Koch
  • Robinia cornigera K.Koch
  • Robinia crispa K.Koch
  • Robinia cylindrica K.Koch
  • Robinia decaisneana Verl.
  • Robinia dissecta Verl.
  • Robinia echinata Mill.
  • Robinia edwardsiifolia Verl.
  • Robinia fastigiata Verl.
  • Robinia fastigiataaureovariegata Jacob-Makoy
  • Robinia fragilis Salisb.
  • Robinia inermis fastigiata-aureovariegata Jacob-Makoy
  • Robinia inermis Jacq.
  • Robinia inermis pendula Paul
  • Robinia inermis var. rehderi Ed.Otto
  • Robinia jaspidea Verl.
  • Robinia latisiliqua Verl.
  • Robinia linearis K.Koch
  • Robinia ludoviciana Raf.
  • Robinia microphylla Loudon
  • Robinia monophyllus K.Koch
  • Robinia myrtifolia G.Nicholson
  • Robinia patula Verl.
  • Robinia pendula Ortega
  • Robinia pendulina Sweet
  • Robinia pinnata Steud.
  • Robinia pringlei Rose
  • Robinia procera Lodd. ex G.Don
  • Robinia pseudoacacia f. amorphifolia (Loudon) Rehder
  • Robinia pseudoacacia f. atropurpurea Dippel
  • Robinia pseudoacacia f. aurea (G.Kirchn.) Rehder
  • Robinia pseudoacacia f. bessoniana (G.Nicholson) Voss
  • Robinia pseudoacacia f. coluteoides (Neumann) Rehder
  • Robinia pseudoacacia f. crispa (DC.) Rehder
  • Robinia pseudoacacia f. decaisneana (Carrière) Voss
  • Robinia pseudoacacia f. dependens Rehder
  • Robinia pseudoacacia f. dissecta (Mottet) Rehder
  • Robinia pseudoacacia f. erecta Rehder
  • Robinia pseudoacacia f. frisia W.Jansen ex Geerinck
  • Robinia pseudoacacia f. inermis (DC.) Rehder
  • Robinia pseudoacacia f. linearis (G.Kirchn.) Rehder
  • Robinia pseudoacacia f. microphylla (Lodd. ex Loudon) Rehder
  • Robinia pseudoacacia f. monophylla-pendula (Dieck) Voss
  • Robinia pseudoacacia f. myrtifolia (K.Koch ex C.K.Schneid.) Rehder
  • Robinia pseudoacacia f. oswaldiae Oswald
  • Robinia pseudoacacia f. pendula (Ortega) Rehder
  • Robinia pseudoacacia f. pendula C.K.Schneid.
  • Robinia pseudoacacia f. purpurea Dippel
  • Robinia pseudoacacia f. pyramidalis (Pépin) Rehder
  • Robinia pseudoacacia f. rehderi (Ed.Otto) C.K.Schneid.
  • Robinia pseudoacacia f. rozynskiana (Späth ex C.K.Schneid.) Rehder
  • Robinia pseudoacacia f. semperflorens (Carrière) Voss
  • Robinia pseudoacacia f. stricta (Loudon) Rehder
  • Robinia pseudoacacia f. tortuosa (DC.) Rehder
  • Robinia pseudoacacia f. ulriciana (Reut. ex Hartwig) Rehder
  • Robinia pseudoacacia f. umbraculifera (DC.) Rehder
  • Robinia pseudoacacia f. unifoliata (Talou) Rehder
  • Robinia pseudoacacia monophylla-fastigiata Dieck
  • Robinia pseudoacacia monophylla-pendula Dieck
  • Robinia pseudoacacia pyramidalis Pépin
  • Robinia pseudoacacia subsp. crispa (DC.) Arcang.
  • Robinia pseudoacacia subsp. inermis (Jacq.) Arcang.
  • Robinia pseudoacacia subsp. tortuosa (Hoffmanns.) Arcang.
  • Robinia pseudoacacia subsp. umbraculifera (DC.) Arcang.
  • Robinia pseudoacacia var. amorphifolia Loudon
  • Robinia pseudoacacia var. angustifolia Lej.
  • Robinia pseudoacacia var. aurea G.Kirchn.
  • Robinia pseudoacacia var. bessoniana G.Nicholson
  • Robinia pseudoacacia var. coluteoides Neumann
  • Robinia pseudoacacia var. crispa DC.
  • Robinia pseudoacacia var. decaisneana Carrière
  • Robinia pseudoacacia var. dissecta Mottet
  • Robinia pseudoacacia var. inermis DC.
  • Robinia pseudoacacia var. linearis G.Kirchn.
  • Robinia pseudoacacia var. microphylla Lodd. ex Loudon
  • Robinia pseudoacacia var. monophylla Carrière
  • Robinia pseudoacacia var. monophylla-pendula (Dieck) Hartwig
  • Robinia pseudoacacia var. myrtifolia K.Koch ex C.K.Schneid.
  • Robinia pseudoacacia var. pendula (Ortega) Loudon
  • Robinia pseudoacacia var. pendulifolia G.Kirchn.
  • Robinia pseudoacacia var. pyramidalis (Pépin) C.K.Schneid.
  • Robinia pseudoacacia var. rectissima Raber
  • Robinia pseudoacacia var. rozynskiana Späth ex C.K.Schneid.
  • Robinia pseudoacacia var. semperflorens Carrière
  • Robinia pseudoacacia var. sophorifolia Lodd. ex Loudon
  • Robinia pseudoacacia var. stricta Loudon
  • Robinia pseudoacacia var. tortuosa DC.
  • Robinia pseudoacacia var. ulriciana Reut. ex Hartwig
  • Robinia pseudoacacia var. umbraculifera (DC.) DC.
  • Robinia pseudoacacia var. unifoliata Talou
  • Robinia pseudoacacia var. vulgaris Lej.
  • Robinia pyramidalis Pépin
  • Robinia pyramidalis Verl.
  • Robinia sophorifolia Besser
  • Robinia spectabilis Dum.Cours.
  • Robinia stricta Hoffmanns.
  • Robinia tortuosa Hoffmanns.
  • Robinia umbraculifera DC.
  • Robinia undulata K.Koch
  • Robinia uterhartii Rousselon
Suggest a Correction

Introduction

Black locust is the largest, most economically important, and most widely planted member of Robinia. It is a fast-growing deciduous tree with furrowed bark, pinnate leaves, paired stipular spines most conspicuous on young growth, and pendulous racemes of fragrant white flowers. Its native distribution is eastern North America, centered in and around the Appalachian region with additional native populations farther west, but cultivation has carried it through much of the temperate world. As a result, a black locust growing in North America or Europe may be native, planted, naturalized, or the clonal descendant of a long-abandoned planting. (Cierjacks et al. 2013; Royal Botanic Gardens, Kew 2026)

Species identity is not a major taxonomic problem. The complexity lies instead in clonality, horticultural variation, extensive human movement, and hybridization with other Robinia. Tree TSAR recognizes named hybrids linking black locust with R. viscosa, R. hispida, and R. neomexicana. Wheeler also detected a strong introgression signal between R. pseudoacacia and the single sampled accession of R. hispida var. kelseyi, reinforcing the conclusion that gene exchange occurs within the genus even when a parent species remains morphologically recognizable. (Wheeler 2023)

The species has accumulated an exceptionally large synonymy through more than two centuries of horticultural selection. Tree TSAR does not convert that cultivar history into botanical infraspecific taxa. In particular, the historical name R. pseudoacacia var. rectissima is represented horticulturally as R. pseudoacacia ‘Rectissima’, the shipmast-locust cultivar, rather than as an accepted variety or a separate taxon page. (Royal Botanic Gardens, Kew 2026)

Horticultural and Agricultural Uses

Few temperate trees combine black locust’s speed of juvenile growth with such durable wood. The heartwood is naturally decay-resistant and mechanically strong, supporting use for fence posts, outdoor construction, poles, furniture, and other products where durability matters. European forestry has also developed black locust as a plantation and coppice tree, and recent wood reviews continue to identify favorable strength, dimensional stability, and outdoor performance. (Nicolescu et al. 2020; Porojan & Manea Salca 2026)

Black locust’s rapid regrowth, root suckering, and symbiotic nitrogen fixation have also made it an important reclamation and biomass tree. Plantings on degraded and mined land can influence much more than above-ground vegetation: long-term restoration stands have been shown to shift soil carbon toward microbially derived and mineral-associated pools, while shelterbelts at a Greek mining site substantially reduced environmental noise exposure. Performance on difficult sites depends in part on below-ground partners; inoculation with salt-tolerant rhizobia and arbuscular mycorrhizal fungi can improve ion balance and reduce salinity stress. These responses help explain both the usefulness of black locust in restoration and the importance of matching provenance, microbial partners, and site conditions rather than assuming that every planting will behave identically. (Zafar et al. 2026; Sachanidis et al. 2026; Hui et al. 2026)

Commercial seed production must also account for clonality. Pakull and colleagues found stands in which many apparent trees represented very few multilocus genotypes; seed collected from such stands can therefore sample much less parental diversity than stem counts imply. For genetically diverse forest reproductive material, they recommend considering clonal stand structure and favoring well-designed seed orchards. (Pakull et al. 2024)

The species also remains an important ornamental, honey, and multipurpose agroforestry tree. Cultivars have been selected for crown form, foliage, armature, flowering, and production traits, and recent Hungarian work suggests that foliage from selected clones may have value as a complementary fermented livestock feed. That application remains experimental, especially because pods contain antinutritional proteins, but it illustrates how the same biological attributes that made black locust a traditional timber and reclamation tree continue to generate new uses. (Tömösközi-Farkas et al. 2026)

Conservation Concerns

Black locust presents two nearly opposite conservation stories. Within its native range it is a widespread native tree and is not considered globally threatened. Outside that range, however, it is one of the most successful naturalized North American trees and is considered invasive in many regions. Root suckering, rapid growth after disturbance, nitrogen fixation, prolific flowering and seed production, and repeated human planting can help it form persistent stands. (Cierjacks et al. 2013; Kato-Noguchi & Kato 2024; Royal Botanic Gardens, Kew 2026)

In invaded open habitats, black locust can change light regimes, vegetation structure, soil nitrogen, and successional trajectories. Management is complicated by its capacity to resprout vigorously after cutting, so simple one-time removal may stimulate rather than end clonal recruitment. Current bioenergy discussions therefore emphasize a genuine tradeoff: a rapidly growing woody resource may be valuable on carefully managed marginal land while creating unacceptable ecological costs near vulnerable habitats. (Kato-Noguchi & Kato 2024; Calandrelli & De Masi 2026)

The species’ global abundance should not make native genetic resources invisible. Historic movement and plantation selection have redistributed a subset of black-locust diversity far beyond the original range, while extensive clonality can reduce the number of genotypes represented within a stand. Conserving native populations, documenting provenance, and maintaining broad genetic representation in breeding and seed programs are therefore complementary to invasive-species control elsewhere. (Pakull et al. 2024)

Additional Information

References and Further Reading

Calandrelli MM, De Masi L (2026) Impact and prospects of the invasive alien plant Robinia pseudoacacia L. as a bioenergy resource. Agronomy 16(11): 1036. https://doi.org/10.3390/agronomy16111036

Cierjacks A, Kowarik I, Joshi J, Hempel S, Ristow M, von der Lippe M, Weber E (2013) Biological Flora of the British Isles: Robinia pseudoacacia. Journal of Ecology 101(6): 1623-1640. https://doi.org/10.1111/1365-2745.12162

Hui Q, Li S, Chen Z, Zhang R, Hou R, Efrose R, Flemetakis E, Hu B, Rennenberg H (2026) Inoculation with salt-tolerant rhizobia and AMF regulates K+/Na+ homeostasis in Robinia pseudoacacia L. alleviating salinity. Plant, Cell & Environment 49(7): 4116-4133. https://doi.org/10.1111/pce.15621

Kato-Noguchi H, Kato M (2024) Invasive characteristics of Robinia pseudoacacia and its impacts on species diversity. Diversity 16(12): 773. https://doi.org/10.3390/d16120773

Nicolescu V-N, Redei K, Mason WL, Vor T, Poetzelsberger E, Bastien J-C, Brus R, Bencat T, Dodan M, Cvjetkovic B, et al. (2020) Ecology, growth and management of black locust (Robinia pseudoacacia L.), a non-native species integrated into European forests. Journal of Forestry Research 31: 1081-1101. https://doi.org/10.1007/s11676-020-01116-8

Pakull B, Schneck V, Liesebach H (2024) Clonality in black locust (Robinia pseudoacacia L.) and implications for seed production. Annals of Forest Science 81: 39. https://doi.org/10.1186/s13595-024-01257-4

Porojan M, Manea Salca E-A (2026) Black locust (Robinia pseudoacacia L.) wood: a review of material properties, characterization, and industrial potential in Europe. Forests 17(7): 841. https://doi.org/10.3390/f17070841

Royal Botanic Gardens, Kew (2026) Robinia pseudoacacia L. Plants of the World Online.

Sachanidis C, Kiorapostolou N, Eleftheriadou N, Fotelli MN, Markos N, Fyllas NM, Radoglou K (2026) Black locust restoration plantations reduce noise exposure at a mining area in Greece. Forests 17(6): 690. https://doi.org/10.3390/f17060690

Trees and Shrubs Online (2026) Robinia pseudoacacia. International Dendrology Society.

Tömösközi-Farkas R, Lengyel-Kónya E, Berki M, Zalán Z, Takács K, Szerdahelyi E, Horváth-Szanics E, Adányi N, Borovics A, Rásó J, et al. (2026) Investigating the usability of black locust (Robinia pseudoacacia L.) cultivars for feed purposes in Hungary. Agroforestry Systems 100: 170. https://doi.org/10.1007/s10457-026-01553-0

Wheeler B (2023) Molecular and Morphological Tests of Species Delimitation in Robinia of the Southern Appalachians. MS thesis, Western Carolina University.

Zafar A, Hu Y, Wang S, Mustafa A, Han K, Gunina A, Mehran M, Shen W (2026) Shifts in plant- and microbe-derived carbon pathways during forest restoration drive soil carbon stabilization in Mu Us Sandy Lands. Environmental Science & Technology 60(22): 15781-15795. https://doi.org/10.1021/acs.est.5c15181