Solanum campylacanthum
2n=24, 48 (see Knapp et al. 2013 for references)
Ubiquitous weed of low altitudes in southern and eastern Africa from Kenya south to South Africa; growing along roadsides, in abandoned cultivation, savanna, bushland, dunes, and forest edges, and in a wide variety of disturbed habitats; 0-2000 (-2300) m.
Solanum campylacanthum is a member of the Eggplant clade and a close relative of the cultivated eggplant, Solanum melongena (Vorontsova et al. 2013). The Eggplant Clade is a monophyletic group within the Old World clade of the spiny solanums (Leptostemonum Clade). For a synopsis of membership see Knapp et al. 2013.
Bitter, G. 1923. Solana Africana. IV. Repert. Spec. Nov. Regni Veg., Beih.. 16: 1-320.
Cronk, Q. C. B. 1998. The ochlospecies concept. In Chorology, taxonomy and ecology of the floras of Africa and Madagascar, ed. C. R. Huxley, J. M. Lock, and D. F. Cutler, 155-170. Kew: Royal Botanic Gardens, Kew.
Daunay, M-C., R. N. Lester, and G. Ano. 2001. Eggplant. In Tropical plant breeding, ed. A. Charrier, M. Jacquot, S. Hamon, and D. Nicolas, 199-222. Enfield, Plymouth: Science Publishers Inc.
Friis, I. 2006b. Solanaceae. In Flora of Somalia vol. 3, ed. M. Thulin, 206-219. Kew: Royal Botanic Gardens, Kew.
Knapp, S., M. S. Vorontsova, and J. Prohens. 2013. Wild relatives of the eggplant (Solanum melongena L.: Solanaceae): new understanding of species names in a complex group. PLoS ONE 8(2): e57039. doi:10.1371/journal.pone.0057039.
Olet, E. A., and R. Bukenya-Ziraba. 2001. Variation within the Solanum incanum complex in Uganda and its relationship with Solanum cerasiferum. In: van den Berg R. G., Barendse G. W. M, van der Weerden G. M., Mariani C., eds. Solanaceae V: Advances in Taxonomy and Utilization. Botanical Garden of Nijmegen: Nijmegen University Press, 97-108.
Vorontsova, M. S., and S. Knapp. 2010. Lost Berlin (B) types of Solanum (Solanaceae) – found in Göttingen (GOET). Taxon 59: 1585-1601.
Vorontsova, M. S., S. Stern, L. Bohs, and S. Knapp. 2013. African spiny Solanum (subgenus Leptostemonum, Solanaceae): a thorny phylogenetic tangle. Bot. J. Linn. Soc. 173: 176-193. doi:10.1111/boj.12053
White, F. 1962. Geographic variation and speciation in Africa with particular reference to Diospyros. In Taxonomy and Geography. Publ. Syst. Assoc. 4: 71-103.
Local Names (languages in parentheses). Angola: Matumbiriri (Lunyaneka). Democratic Republic of the Congo: Kalumbalumba (Luba). Ethiopia: Angulle Angulle; Etulele (Nyangatom); Garinti (Ari); Moh, Omboi (Amharic); Tirkit, Turkit, Turkett (Bodi). Kenya: Esikilele, Etelolo, Etilolo (Turkana); Da' ur (Somali); Endulelei, Intuleile i (Masai); Hiddi, Hiddi looni, Hidi (Boran); Ilitoratora (Kikuyu); Indalandalwa (Luhya); Intuteliot (Dorobo); Ioi (Boran); I-tulelei (Njemps); Kikondu, Mukondu (Kamba); Kiondu kinene (Kamba); Labotwa (Marakwet); Labotwet, Oloulele (Kipsigis); Lopotwa, Lopotwo (Pokot); Ltulelei (Samburu); Mtando; Mtunguja mwilu (Swahili); Mtondo (Giriama); Mtungudza koma; Mukondu (Digo, Kamba); Mtunguja (Swahili); Mtunguza koma (Digo); Mukondu (Kamba); Mutongu (Meru, Kikuyu); Ndulelei, Ndurerei, Ntulelei (Samburu); Ochok (Luo); Omoratara (Kisii); Ootobo (Kisii); Sodom apple; Yohola (Rendille). South Africa: N'toma (Zulu). Sudan: Naarim (Imatong). Tanzania: Bwanhula, Bwantula (Zaramo); Endellelei (Masai); Entoboro (Kerewe); Kitatula (Baluhia); Mitunguluja (Kimbunga); Mtuntula (Kiswheli, Kibemba); Mtula (Kishamba); Mtula (Zaramo); Mtungurusa (Ngoni); Nduo (Nyakiwa, Cheg); Mtura (Swahili); Mtuwa (Bondei, Kibondei); Mutongu (Kikuyu); Ndula (Bena, Hehe); Ndula (Kihehe); Ndwa (Kimeru); Ntufururu (Kibonde); Shaboik (Tatog); Tunguja (Tongwe, Swahili). Uganda: Ekitobutobu (Ankole); Ntulantula (Luganda, Lusoga). Zimbabwe: Munhundurwa.
Uses. Fruits and roots used medicinally and as poison in Tanzania, Kenya, and Uganda.
Least Concern (LC); a widespread, semi-invasive weed. Further investigation of ploidy differentiation may reveal populations worthy of protection (Knapp et al. 2013).
Solanum campylacanthum is a familiar species to anyone visiting northeastern or southern Africa, omnipresent in almost any disturbed environment between sea level and 2000 m elevation. A perennial weed flowering and fruiting abundantly throughout the year, it has mauve flowers, large bright yellow fruits, a long taproot, and usually entire leaves that are often quite large. Comparing isolated specimens of S. campylacanthum creates the impression of numerous species and indeed, 84 names have been published and 23 species and 36 infraspecific taxa were recognized by Bitter (1923) within our concept of S. campylacanthum. Observation of the stands of S. campylacanthum growing throughout Africa and comparison of thousands of herbarium specimens reveals that the morphological variation is actually continuous, with similar variants occurring randomly in different parts of the population, e.g. the presence of curved prickles or obtuse leaf lobes is rare but equally likely in Ethiopia, Kenya, or Mozambique. Solanum campylacanthum does not usually reach above 1.5 m in height, but in the forests of upland Kenya it can grow up to 4 m; the surprising extent of the variation in Kenya has been documented by Robinson (1993). The only morphological character consistently varying with geographical distribution is the occurrence of smaller size and smaller, longer, and narrower leaves south of around 20°S. These smaller plants with long narrow leaves were variously recognized by Jaeger and Lester as S. panduriforme or S. delagoense. We include these under S. campylacanthum as the morphological cline is continuous with no marked geographical discontinuity from north to south.
This treatment and the accompanying illustrations aim to capture as much as possible of the diversity of this species. The majority of published treatments fail to include the full variability of species such as S. campylacanthum, leading to failure to recognize the extent of variability exhibited by many plants, as well as confusion during specimen identification. The recognition of this species entity is supported by crossing results: groups A (S. campylacanthum sensu Lester) and B (S. panduriforme sensu Lester) are interfertile and distinct from other eggplant wild relatives (Daunay et al. 2001). By his own admission, Lester’s herbarium specimen-based research reached a limit of its usefulness and further understanding of the variability of this species requires population studies to be carried out in its natural habitat (Olet & Bukenya-Ziraba 2001).
The concept of “ochlospecies” was proposed by Frank White (White 1962; Cronk 1998) for hypervariable species where variability is not due to a specialised breeding system and has weak correlation with other characters or with distribution. These species are often widespread and weedy, with multiple synonyms and several smaller “satellite” species. All the criteria for ochlospecies are fulfilled by both S. anguivi and S. campylacanthum, and more so by the latter as the variation is greater (although similarly apparently random).
Although Friis (2006b) cited the sheet of Senni 220 in FT as the “holotype” of S. senni Chiovenda (1932) did not cite specific herbaria in his protologue nor in the introductory matter for the second volume of Flora somala. We designate this sheet as the lectotype here; no other duplicates have been found.
A poor pencil leaf tracing at GOET is the only known image of the original material of S. repandifrons (Stuhlmann 8273 incorrectly written as Stuhlmann 873 in Vorontsova & Knapp 2010). Although we suggested this name might need to be neotypified, we have not done so here, following the practice we have set for other synonyms with no extant original material or duplicates thereof.
In describing S. campylacanthum var. mollius, Bitter (1923) cited “Schimper 304 ex parte( ex herb. Mus. Paris, herb. Berol.)”, suggesting he was describing the variety from a fragment off a sheet that remained in Paris (he also stated the specimen was from no particular locality in “Abyssinien” = today’s Ethiopia). Of the three sheets of Schimper 304 in P, one is annotated by Bitter and all are clearly duplicates of the same Schimper gathering. We have selected P00344533 as the lectotype because it has the original label, is the most complete specimen with flowers and fruit, and matches the protologue in having softly hairy leaves.