Solanaceae Source

A global taxonomic resource for the nightshade family

Identification keys

The Identification Keys


Solanum          


These electronic multi-access keys to Solanum were constructed by the Solanum Key Consortium (led by Rebecca Hilgenhof) in 2020.  The identification key runs on Xper3 software, which allows the building of structured knowledge bases and online free-access keys. 

  • Contributors to the Solanum Key Consortium (in alphabetical order by surname) - Xavier Aubriot, Gloria Barboza, Lynn Bohs, Franco E. Chiarini, Rocío Deanna, Leandro Giacomin, Yuri Gouvêa, Rebecca Hilgenhof, Sandra Knapp, Chris Martine, Andres Orejuela, Clara Ines Orozco, Iris E. Peralta, Tiina Särkinen, João R. Stehmann, Eric Tepe
  • Photographs used in the key were contributed by (in alphabetical order by surname): Pedro Acevedo Rodríguez, Gloria E. Barboza, Michael Benedito, Gabriel Beltrán, Lynn Bohs, Asunción Cano, Franco Chiarini, John L. Clark, Max Coleman, Rocio Deanna, Martin Gardner, Leandro Giacomin, Paul Gonzales, Mariano Gorostiza Salazar, Yuri Gouvêa, David Goyder, William Haber, Paulina Hechenleitner, Rebecca Hilgenhof, Bente Klitgaard, Gwilym Lewis, Chris Martine, Alex Monro, Michael Nee, Patricio Novoa Quezada, Pieter Pelser, Sandra Knapp, David Rae, Tony Rebelo, David Spooner, João R. Stehmann, Stephen Stern, Eric Tepe, Juan D. Tovar, Mario Vallejo-Marín, Maria Vorontsova, Kim Watson, John R.I. Wood, Dani Zamir

For a quick pdf guide to how to use the key click here.

For a file with links to some images of herbarium specimens to test how the Xper3 multi-access key works click here. We advise testing the key with these known specimens first - it helps!

Please use the following to cite these keys -

For how to cite Solanaceae Source click here

To alert us to mistakes or to give us feedback please contact Tiina Särkinen (t.sarkinen@rbge.ac.uk) or Sandra Knapp (s.knapp@nhm.ac.uk)


Keys to the groups (clades or single species that have no close relatives) of Solanum

Global multi-access key to all groups of Solanum

  • Use this Xper3 key to find out the Solanum group your plant or specimen belongs to and find the right species-level key to use from the list below.

Keys to Solanum species

Thelopodium and Clade I global multi-access key

  • This Xper3 key covers non-spiny species only; if you have a spiny specimen, see the guide to previously published dichotomous species-level keys below (listed by group in alphabetical order).
  • Includes species of the wild tomato (Tomato group), wild Potato (Petota group), African Non-Spiny, Anarrhichomenum, Archaeosolanum, Articulatum, Basarthrum, Dulcamaroid, Etuberosum, Herpystichum, Morelloid, Normania, Oxycoccoides, Pteroidea, Regmandra, Valdiviense, and Thelopodium clades
  • Focuses on characters available on your specimen
  • Choose multiple options per character
  • Learn to use characters with our Quick guide to using the keys and to a list of digital images of Practise specimens to tune your eye
  • Key characters: Geography, Prickles, Fruit & corolla colour, Pedicel articulation & base, Pseudostipules, Pairing of leaves, Leaf type & margin


Published dichotomous keys to groups of Solanum species (alphabetical order)

Group names come largely from the phylogenetic framework of the family Solanaceae published in Särkinen et al. (2013), with additional groups as revealed in ongoing phylogenetic analyses of Solanum as a whole with larger sampling.  


African Solanum (all species, native and introduced) 

  • Knapp et al. (2019) Dichotomous keys to the species of Solanum L. (Solanaceae) in continental Africa, Madagascar (incl. the Indian Ocean islands), Macaronesia and the Cape Verde Islands. PhytoKeys 127: 39-76.


Acanthophora group 

  • Global key: under construction by Franco Chiarini and Sandy Knapp.
  • Overview: Levin et al. (2005) A four-gene study of evolutionary relationships in Solanum section Acanthophora. American Journal of Botany 92: 603-612. 
  • Key to species with flattened or winged seeds from Brazil and Argentina: Chiarini & Mentz (2012) A new species of Solanum sect. Acanthophora (Solanaceae) from Argentina and Brazil. PhytoKeys 18: 1-10.

African Non-Spiny group   

  • Included in the Global multi-access key to Thelopodium & Clade I
  • Global key: Knapp & Vorontsova (2016) A revision of the “African Non-Spiny” Clade of Solanum L. (Solanum sections Afrosolanum Bitter, Benderianum Bitter, Lemurisolanum Bitter, Lyciosolanum Bitter, Macronesiotes Bitter, and Quadrangulare Bitter: Solanaceae). PhytoKeys 66: 1–142.


Allophyllum group 


Anarrhichomenum group 


Androceras group 


Anomalostemon group 

  • The "group" currently consists of a single species: Knapp & Nee (2009) Solanum anomalostemon (Solanaceae), an endangered new species from southern Peru with unusal anther morphology. Novon 19: 178-181.


Archaeosolanum group 


Articulatum group  


Asterophorum group 


Bahamense group 

  • Global key: Strickland-Constable et al. (2010) Species identity in the Solanum bahamense species group (Solanaceae, Solanum subgenus Leptostemonum). Taxon 59: 209-226. 


Basarthrum group 

  • Included in the Global multi-access key to Thelopodium & Clade I
  • Global key: not yet under construction, the group is not being actively worked on. Recent material collected in Peru indicates there are new species remaining to be described in this group.
  • Overview: Tepe et al. (2016). Relationships among wild relatives of the tomato, potato, and pepino. Taxon 65: 262-276.
  • Small key to some species: Anderson (1975) The variation and evolution of selected species of Solanum section Basarthrum. Brittonia 27: 209-222.


Brevantherum group 

  • Global key: under construction by Leandro Giacomin.
  • Overview: Roe (2072). A revision of Solanum section Brevantherum (Solanaceae). Brittonia 24: 239-278. 


Campechiense group 

  • The "group" currently consists of a single species (S. campechiense)
  • Overview: Stern et al. (2011) Molecular delimitation of clades within New World species of the ‘spiny solanums’ (Solanum subg. Leptostemonum). Taxon 60: 1429-1441.


Carolinense group  


Crinitum group 

  • Global key: under construction by Frank Farrugia et al.
  • Key to extra-Amazonian Brazilian species: Gouvêa et al. (2019) Solanum medusa (Solanaceae), a new wolf-fruit from Brazil, and a key to the extra-Amazonian Brazilian Androceras/Crinitum clade species. PhytoKeys 118: 15-32
  • Key to Andean species: Farrugia & Bohs (2010) Two new South American species of Solanum section Crinitum (Solanaceae). PhytoKeys 1: 67-77.

Cyphomandra (Pachyphylla) group 

  • Global key: Bohs (1994) Cyphomandra (Solanaceae). Flora Neotropica 63: 1-175.
  • Name transfers from Cyphomandra to Solanum: Bohs (1995) Transfer of Cyphomandra (Solanaceae) and its species to Solanum. Taxon 44: 583-587. 
  • Overview: Bohs (2007) Phylogeny of the Cyphomandra clade of the genus Solanum (Solanaceae) based on ITS sequence data. Taxon 56: 1012-1026.


Cyphomandropsis group 


Dulcamaroid group 


Elaeagnifolium group 

  • Global key: Knapp et al. (2017) A revision of the Solanum elaeagnifolium clade (Elaeagnifolium clade; subgenus Leptostemonum, Solanaceae). PhytoKeys 84: 1-104. 


Erythrotrichum group 

  • Global key: Agra (2008) Four new species of Solanum section Erythrotrichum (Solanaceae) from Brazil and Peru, and a key to the species of the section. Systematic Botany 33: 556-565.
  • Overview: Agra (2004) Sinopse taxonômica de Solanum sect. Erythrotrichum (Solanaceae). Pp. 192–211 in: Rangel-C, Aguirre, Andrade-C & Cañas (eds.), Memorias Octavo Congresso Latinoamericano e Segundo Colombiano de Botánica. Bogotá: Universidad Nacional de Colombia.


Etuberosum group 

  • Included in the Global multi-access key to Thelopodium & Clade I
  • Global key: Contreras-M & Spooner et al. (1999) Revision of Solanum section Etuberosum (subgenus Potatoe). In Nee, Symon, Lester & Jessop (eds.), Solanaceae IV, pp. 227-245. Royal Botanic Gardens, Kew. 
  • Global key (updated): Spooner et al. (2017) Taxonomy of wild potatoes and their relatives in southern South America (Solanum sects. Petota and Etuberosum). Systematic Botany Monographs 100: 1-236. 

Euacanthum group 

  • The "group" currently consists of a single species (S. euacanthum)


Gardneri group 

  • Global key: under construction.
  • Overview: Stern et al. (2011) Molecular delimitation of clades within New World species of the ‘spiny solanums’ (Solanum subg. Leptostemonum). Taxon 60: 1429-1441.


Geminata group 

  • Global key: Knapp (2008) A revision of the Solanum havanense species group and new taxonomic additions to the Geminata clade (Solanum, Solanaceae). Annals of the Missouri Botanical Garden 95: 405-458. 
  • Key to Brazilian species: Knapp et al. (2015) New species, additions and a key to the Brazilian species of the Geminata clade of Solanum L. (Solanaceae) in Brazil. PhytoKeys 47: 1-48.


Gonatotrichum group 


Herpystichum group 


Inornatum group 

  • Global key: Giacomin et al. (2014) Three new species of Solanum (Brevantherum clade) endemic to the Brazilian Atlantic Forest. PhytoKeys 38: 69-87.


Lasiocarpa group 


Micracantha group 

  • Global key: under construction by Stephen Stern
  • Overview: Stern et al. (2011) Molecular delimitation of clades within New World species of the ‘spiny solanums’ (Solanum subg. Leptostemonum). Taxon 60: 1429-1441.


Morelloid group 

  • Included in the Global multi-access key to Thelopodium & Clade I
  • Key to Old World: Särkinen et al. (2018) A revision of the Old World Black Nightshades (Morelloid clade of Solanum L., Solanaceae). PhytoKeys 106: 1-223.
  • Key to North and Central America and the Caribbean: Knapp et al. (2019) A revision of the Morelloid Clade of Solanum L. (Solanaceae) in North and Central America and the Caribbean. PhytoKeys 123: 1-144.
  • Key to Argentina: Barboza et al. (2013) Solanum Grupo VII. Moreloide. In: Barboza (coord.), Flora Argentina: Flora vascular de la Republica Argentina, Vol. 13, pp. 231–264. San Isidro: Instituto de Botanica Darwinion.
  • Overview: Särkinen et al. (2015) True Black nightshades: Phylogeny and delimitation of the Morelloid clade of Solanum. Taxon 64: 945-958.

Multispinum group 

  • The "group" currently consists of a single species (S. multispinum)
  • Overview: Stern et al. (2011) Molecular delimitation of clades within New World species of the ‘spiny solanums’ (Solanum subg. Leptostemonum). Taxon 60: 1429-1441.


Nemorense group 


Normania group 


Old World Leptostemonum group(s) 

  • Overview: Whalen (1984) Conspectus of species groups in Solanum subgenus Leptostemonum. Gentes Herbarum 12: 179-282.
  • Key to African and Malagasy species: Vorontsova & Knapp (2016) A revision of the ‘Spiny Solanums’, Solanum subgenus Leptostemonum (Solanaceae), in Africa and Madagascar. Systematic Botany Monographs 100: 1-432.
  • Key to Australian species: Symon (1981) A revision of the genus Solanum in Australia. Journal of Adelaide Botanical Gardens 4: 1-367.
  • Key to Queensland species: Bean (2004) The taxonomy and ecology of Solanum subg. Leptostemonum (Dunal) Bitter (Solanaceae) in Queensland and far north-eastern New South Wales, Australia. Austrobaileya 6: 639-816.
  • Key to New Guinean species: Symon (1985) The Solanaceae of New Guinea. Journal of Adelaide Botanical Gardens 8: 1-171.
  • Key to Eggplant clade: Knapp et al. (2013) Wild relatives of the eggplant (Solanum melongena L.: Solanaceae): New understanding of species names in a Complex Group. PLoS ONE 8: e57039.
  • Key to Echinatum clade: Bean (2012) A taxonomic revision of the Solanum echinatum group (Solanaceae). Phytotaxa 57: 33-50.
  • Key to Asian species: under construction by Xavier Aubriot and Sandy Knapp, see overview in Aubriot et al. (2016) Tropical Asian species show that the Old World ‘spiny solanums’ (Solanum subgenus Leptostemonum pro parte: Solanaceae) is not monophyletic. Botanical Journal of the Linnean Society 181: 199-223.
  • Revision of Petrophilum complex with recently described species: Bean (2016) The Solanum petrophilum complex (Solanaceae) revised, with the description of three new species. Journal of the Adelaide Botanic Gardens 29: 23-36.

Oxycoccoides group 

  • The "group" currently consists of a single species and has been treated as part of a larger work on the Potato clade: Tepe et al. (2016). Relationships among wild relatives of the tomato, potato, and pepino. Taxon 65: 262-276. 


Petota group 

  • Included in the Global multi-access key to Thelopodium & Clade I
  • Overview: Spooner et al. (2014) Systematics, diversity, genetics, and evolution of wild and cultivated Potatoes. Botanical Review 80: 283-383.
  • Key to the cultivated species: Ovchinnikova et al. (2011) Taxonomy of cultivated potatoes (Solanum section Petota: Solanaceae). Botanical Journal of the Linnean Society 165: 107-155.
  • Key to southern South America: Spooner et al. (2016) Taxonomy of wild potatoes and their relatives in southern South America (Solanum sects. Petota and Etuberosum). Systematic Botany Monographs 100: 1-238. 
  • Key to northern South America: Spooner & Jansky (2019) Taxonomy of wild potatoes in northern South America (Solanum section Petota). Systematic Botany Monographs 108: 1-305. 
  • Key to North & Central America: Spooner et al. (2004) Wild potatoes (Solanum section Petota: Solanaceae) of North and Central America. Systematic Botany Monographs 68: 1-209. 

Polygamum group 

  • The "group" currently consists of a single species (S. polygamum)
  • Overview: Stern et al. (2011) Molecular delimitation of clades within New World species of the ‘spiny solanums’ (Solanum subg. Leptostemonum). Taxon 60: 1429-1441.

Pteroidea group 


Reductum group 

  • The group currently consists of two species, one of which (S. delitescens) was previously treated as belonging the Geninata clade by Knapp (2008) A revision of the Solanum havanense species group and new taxonomic additions to the Geminata clade (Solanum, Solanaceae). Annals of the Missouri Botanical Garden 95: 405-458.


Regmandra group 


Sisymbrifolium group 

  • A group of two species (S. sisymbrifolium, S. hasslerianum) treated in Chiarini (2013) Grupo IV. Leptostemonum. In: Barboza (coord.), Flora Argentina: Flora vascular de la Republica Argentina, Vol. 13, pp. 231–264. San Isidro: Instituto de Botanica Darwinion.
  • Overview: Stern et al. (2011) Molecular delimitation of clades within New World species of the ‘spiny solanums’ (Solanum subg. Leptostemonum). Taxon 60: 1429-1441.


Thelopodium group 


Thomasiifolium group 

  • Global key: under construction by Yuri Gouvêa
  • Overview: Stern et al. (2011) Molecular delimitation of clades within New World species of the ‘spiny solanums’ (Solanum subg. Leptostemonum). Taxon 60: 1429-1441.


Tomato group 

  • Included in the Global multi-access key to Thelopodium & Clade I
  • Global key: Peralta et al. (2008) Taxonomy of wild tomatoes and their relatives (Solanum sect. Lycopersicoides, sect. Juglandifolia, sect. Lycopersicon; Solanaceae). Systematic Botany Monographs 84: 1-192. 


Torva group 

  • Global key under construction.
  • Overview: Stern et al. (2011) Molecular delimitation of clades within New World species of the ‘spiny solanums’ (Solanum subg. Leptostemonum). Taxon 60: 1429-1441.


Trachytrichium group 

  • Two woody species from Brazil, related to the Geminata group (Giacomin, in prep.)
  • Previously in part (S. trachytrichium) treated as part of the Geminata group: Knapp (2008) A revision of the Solanum havanense species group and new taxonomic additions to the Geminata clade (Solanum, Solanaceae). Annals of the Missouri Botanical Garden 95: 405-458.


Valdiviense group 


Wendlandii group 

 


Taxonomic name: 
Solanaceae (Solanaceae), Solanum (Solanaceae), Quincula (Solanaceae), Normania (Solanaceae), Cyphomandra (Solanaceae), Melongena (Solanaceae), Triguera (Solanaceae), Lycopersicon (Solanaceae), Quincula lobata (Solanaceae), Solanum asterophorum (Solanaceae), Solanum echinatum (Solanaceae), Solanum echinatum (Solanaceae), Solanum echinatum (Solanaceae), Solanum elaeagnifolium (Solanaceae), Solanum elaeagnifolium (Solanaceae), Solanum melongena (Solanaceae), Solanum melongena (Solanaceae), Solanum petrophilum (Solanaceae), Solanum phoxocarpum (Solanaceae), Solanum thelopodium (Solanaceae), Solanum wendlandii (Solanaceae), Solanum anomalostemon (Solanaceae), Solanum havanense (Solanaceae), Solanum havanense (Solanaceae), Solanum terminale (Solanaceae), Solanum terminale (Solanaceae), Dulcamara (Solanaceae), Solanum abutiloides (Solanaceae), Solanum amotapense (Solanaceae), Solanum asperolanatum (Solanaceae), Solanum bradei (Solanaceae), Solanum carolinense (Solanaceae), Solanum carolinense (Solanaceae), Solanum clandestinum (Solanaceae), Solanum dulcamara (Solanaceae), Solanum endopogon (Solanaceae), Solanum ensifolium (Solanaceae), Solanum etuberosum (Solanaceae), Solanum euacanthum (Solanaceae), Solanum evolvulifolium (Solanaceae), Solanum fragile (Solanaceae), Solanum fragile (Solanaceae), Solanum gardneri (Solanaceae), Solanum hirtum (Solanaceae), Solanum laciniatum (Solanaceae), Solanum laciniatum (Solanaceae), Solanum lycocarpum (Solanaceae), Solanum megalonyx (Solanaceae), Solanum mite (Solanaceae), Solanum monarchostemon (Solanaceae), Solanum montanum (Solanaceae), Solanum montanum (Solanaceae), Solanum multispinum (Solanaceae), Solanum muricatum (Solanaceae), Solanum muricatum (Solanaceae), Solanum nemorense (Solanaceae), Solanum pennellii (Solanaceae), Solanum polygamum (Solanaceae), Solanum polygamum (Solanaceae), Solanum polygamum (Solanaceae), Solanum pyracanthos (Solanaceae), Solanum pyracanthos (Solanaceae), Solanum reductum (Solanaceae), Solanum rostratum (Solanaceae), Solanum rostratum (Solanaceae), Solanum sumacaspi (Solanaceae), Solanum taeniotrichum (Solanaceae), Solanum trisectum (Solanaceae), Solanum tuberosum (Solanaceae), Solanum tuberosum (Solanaceae), Solanum tuberosum (Solanaceae), Solanum turneroides (Solanaceae), Solanum valdiviense (Solanaceae), Solanum viarum (Solanaceae), Solanum brevifolium (Solanaceae), Solanum aethiopicum (Solanaceae), Solanum aethiopicum (Solanaceae), Solanum apiahyense (Solanaceae), Solanum campechiense (Solanaceae), Solanum campechiense (Solanaceae), Solanum campechiense (Solanaceae), Solanum leucopogon (Solanaceae), Solanum oxycoccoides (Solanaceae), Solanum thomasiifolium (Solanaceae)
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith