Solanum anguivi
Not known.
Throughout tropical sub-Saharan Africa, and Madagascar, but not present south of Transvaal and KwaZulu-Natal in South Africa; forest, forest edges, hillsides, savanna, grassland, scrubland, disturbed areas, old cultivation, and roadsides, growing in forests, forest edges, and mountains at 40-3100 m elevation, but the majority of populations occur at 1000-2200 m. For details on habitat and altitude distribution see Dale (1995).
Solanum anguivi is a member of the Old World clade of subgenus Leptostemonum; within that is a member of the large unresolved Anguivi grade (Vorontsova et al. 2013). It is the wild progenitor of the Scarlet Eggplant, Solanum aethiopicum.
Ackland, R. 1995. The use of modern taxonomic techniques to study a group of S. anguivi plants previously classified without significantly detailed study. Undergraduate project, University of Birmingham.
Dale, D. J. 1995. An ecogeographical and phenetic survey of Solanum anguivi in Africa. MSc thesis, University of Birmingham.
D’Arcy, W. G., and A. Rakotozafy. 1994. Solanaceae. Famille 176, pp. 1-146. In Flore de Madagascar et des Comores, P. Morat (ed.). Muséum National D’Histoire Naturelle, Paris.
Friis, I. 2006a. Solanaceae. In Flora of Ethiopia and Eritrea vol. 5, ed. I. Hedberg et al., 103–160 Addis Addis Ababa: Ababa University; Uppsala: Uppsala University.
Gonçalves, A. E. 2005. Solanaceae. In Flora Zambesiaca vol. 8(4), ed. G. V. Pope, R. M. Polhill and E. S. Martins, 1-124. Kew: Royal Botanic Gardens, Kew.
Hepper, F. N. 1978. Typification and name changes of some Old World Solanum species. Bot. J. Linn. Soc. 76: 287-292.
Jaeger, P.-M. L. 1985. Systematic studies in the genus Solanum in Africa. PhD thesis. United Kingdom: University of Birmingham.
Jones, R. 1995. Solanum anguivi s.l.: determination of taxonomic relationships from analysis of seed coat structure and general morphology. Undergraduate project; University of Birmingham.
Lester, R. N., and P. Durrands. 1984. Enzyme treatment as an aid in the study of seed surface structures of Solanum. Ann. Bot. (Oxford) 53: 129-131.
Lester, R. N., and L. Niakan. 1986. Origin and domestication of the scarlet eggplant, Solanum aethiopicum, from S. anguivi in Africa. In Solanaceae: biology and systematics, ed. W.G. D’Arcy, 433-456. New York: Columbia University Press.
Miller, H. S. 1970. The herbarium of Aylmer Bourke Lambert: notes on its acquisition, dispersal, and present whereabouts. Taxon 19: 489-656.
Vorontsova, M. S., and S. Knapp. 2012. Solanum spp. 26-45, 52-62, 65-66. In: J.M. Edmonds, Solanaceae, Flora of Tropical East Africa. Kew: Royal Botanic Gardens, Kew.
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
Local Names (a selection from the many recorded on herbarium specimens). Aboli, Ajuafekghe, Akajabara, Amponimpo, Anguivi, Annsureewia, Annsuroewia, Bakatule, Batula, Bawntay, bwain enye, Bokambo, Botaka, Bouisueguli, Daa-teno, Dotchok, Elolo, Enqui enquai, Entakara, Futa-fula, Hjagi, Itehie, Kinyaju, Losolo, Luanda, Lupangala, Lusu, Magbolei, Maina, Miyau, Mtunguja, Ndagala, Ndakara, Ndereh, Nodasi, N’omboro, Nsusa, Nsusua, Ntula, Ntula-Katunkuma, Ntulwa-Shambaa, Nzua, Obutura, Ocok, Omutakara, Quake, Subalu xunkure, Subulu, Sue, Sufura, Sulujato, Tilinga, Tulele, Ukwo, Umboy, Umukarishya. A more detailed study of local names for this species is beyond the scope of this work. The species epithet originates from the vernacular name used in Madagascar, “anguivi.”
Uses. Fruits eaten; used medicinally in eastern Africa.
Least Concern (LC); a widespread and weedy species.
Solanum anguivi is the second most common and variable species of spiny Solanum in Africa (after S. campylacanthum), and encompasses a great deal of morphological and genetic variation. For many years and in many African floras (see Vorontsova & Knapp 2012) it was known as S. indicum L. (see below). Most representatives of S. anguivi have shallowly lobed leaves with obtuse leaf lobes, straight prickles, short calyx lobes, white flowers, and porrect trichomes with short midpoints. Nevertheless, numerous populations from across Africa exhibit independent occurrences of deeply lobed or subentire leaves, rounded leaf lobes, no prickles, long calyx lobes, mauve flowers, and trichomes with long midpoints. Numerous instances of single morphologically anomalous specimens from different parts of Africa fall within S. anguivi s. l. and it is possible these will be recognized as independent taxa following further research (e.g. the broad-leaved Lythgoe & Evans 592, Ethiopia, K; the small-leaved, few-flowered Gillett 16842, Kenya, EA).
The circumscription of S. anguivi is quite variable among existing treatments. Richard Lester’s research group worked to identify discontinuities in S. anguivi sensu lato using numerical taxonomy (Ackland 1995, Jones 1995, Dale 1995, Lester and Niakan 1986), crossing studies (Lester and Niakan 1986), enzyme electrophoresis (Lester and Niakan 1986), enzyme etching of seed surface (Ackland 1995, Jones 1995), and statistical analyzes of habitat recorded on herbarium specimens (Dale 1995). No natural discontinuity in its variation was observed. We accept a broad concept of S. anguivi here, that includes S. anguivi s. l. as annotated by Lester, including S. anguivi, S. distichum, and S. keniense as recognized by Jaeger (1985), and also including parts of S. adoense and S. usambarense as recognized by Jaeger (1985). This is roughly equivalent to the concept of S. anguivi used by Friis (2006a), Gonçalves (2005), and D’Arcy and Rakotozafy (1994).
Solanum anguivi can be confused with the following partly sympatric African species: S. adoense, S. agnewiorum, S. catombelense, S. macracanthum, S. mauense, S. rubetorum, and S. usambarense. Solanum adoense occurs together with S. anguivi in the mountains of Eritrea, Ethiopia, and Sudan above 1700 m elevation and can be distinguished by its 1-6 berries per inflorescence (versus 6-22 berries per inflorescence in S. anguivi), leaf lobes rounded or absent (versus leaf lobes usually obtuse or acute in S. anguivi), and 1-3 pairs of veins on each leaf (versus 4-7 pairs of veins on each leaf in S. anguivi). Solanum catombelense occurs together with S. anguivi fairly rarely, below 1000 m elevation in Angola, South Africa, Mozambique, and Zimbabwe. Gonçalves (2005) considered S. catombelense to be the southern extension of S. anguivi but S. anguivi actually extends further south in KwaZulu-Natal and the difference between the two taxa is more in elevation, with S. catombelense occurring at higher altitudes. Solanum catombelense can be separated from S. anguivi by its inflorescences with 1-2 fruits per infructescence (versus 6-22 fruits per infructescence in S. anguivi) and entire leaf margins or rounded leaf lobes (versus leaf lobes usually obtuse on S. anguivi). Solanum macracanthum is sympatric with S. anguivi above 2100 m elevation in Ethiopia, and can be distinguished by its ripe fruit 9-13 mm in diameter (versus 6-9 mm diameter in S. anguivi), and calyx 7-12 mm long (versus calyx 3-5 mm long in S. anguivi). Solanum mauense largely replaces S. anguivi in the mountainous regions of the Rift Valley; S. mauense can be identified by its entire or subentire leaves (versus leaves almost always lobed in S. anguivi), the calyx lobes elongating to 4.5-6 mm in fruit (versus calyx lobes elongating to 2.5-5 mm in S. anguivi), and trichomes with stalks 0.15-0.6 mm long (versus trichomes with stalks less than 0.1 mm in S. anguivi). Solanum agnewiorum is sympatric with S. anguivi in central Kenya and can be identified by its acute to acuminate leaf lobes (versus leaf lobes usually obtuse in S. anguivi), and fruit 20-25 mm in diameter (versus fruit 6-9 mm in diameter in S. anguivi). Solanum usambarense is sympatric with S. anguivi in the mountains of northern Tanzania and Kenya, and can be distinguished by its inflorescence axis branching more than once (versus inflorescence axes unbranched or branching only once in S. anguivi), and more than 20 flowers per inflorescence (versus 5-22 flowers per inflorescence in S. anguivi). Solanum rubetorum occurs together with S. anguivi in ZwaZulu-Natal and Transvaal (South Africa) and can be distinguished by its anthers 5.5-7 mm long (versus anthers 3.5-5 mm long in S. anguivi). Other superficially similar species in Tanzania and Mozambique include S. lamprocarpum (low elevation species with foliaceous apically obtuse calyx lobes), S. stipitatostellatum (scrambling plant with larger flowers and fruits), and S. zanzibarense (scrambling low elevation plant with more deeply lobed corollas). In western Africa S. anguivi is frequently misidentified as S. anomalum; S. anomalum can be distinguished by its multangulate trichomes with over 10 rays on each trichome (versus 6-8 rays on each porrect trichome in S. anguivi).
Cultivated forms of S. anguivi are widespread and placed in S. aethiopicum. Solanum anguivi is maintained as a distinct wild to semicultivated species due to its largely distinct morphology, lack of wild intermediates, and a probable selective pressure against hybrids with S. aethiopicum. We follow the circumscription of Richard Lester and place the unarmed Solanum distichum and its synonyms in S. anguivi. Solanum aethiopicum can be identified and distinguished from S. anguivi by a combination of the following characters: annual herbaceous habit, lack of stellate indumentum, smaller and more entire leaves, 1-2 flowers per inflorescence, short and thick pedicels, more than 5 perianth lobes, ovary enlarged even at anthesis, fruit over 1 cm in diameter and with more than two locules, not detaching easily from the pedicels, immature fruit striped and/or not green when immature, and seeds over 2.5 mm long.
For the last 150 years the name “Solanum indicum L.” has been applied to African S. anguivi and Asian S. violaceum, and other superficially similar taxa. Due to historical confusion and widespread misapplication the epithet “indicum” was rejected (Hepper 1978). Richard Lester’s laboratory (Roberts 1978, Niakan 1980, Lester and Durrands 1984, Lester and Niakan 1986) used protein electrophoresis, seed surface enzyme digests and crossing studies to show that S. anguivi is a species distinct from the Asian S. violaceum. The distributions of S. violaceum and S. anguivi do not overlap; the closest proximity of the two species is S. violaceum in Mauritius and S. anguivi in Madagascar. Solanum anguivi occurs across a similarly large geographical range as S. violaceum but is considerably more variable. Solanum violaceum can be distinguished from S. anguivi by its mauve to purple corollas 1.3-3 cm diameter (versus white to pale mauve corollas 0.8-1.5 cm diameter in S. anguivi), anthers 4.5-8.5 mm long (versus anthers 3.5-5 mm long in S. anguivi), fruiting pedicels 1.2-1.8 mm long (versus fruiting pedicels 0.8-1.3 mm long in S. anguivi), and petiole 1/5-3/5 of the leaf length (versus petiole 1/6-1/4 of the leaf length in S. anguivi).
We have not found type specimens for many of the synonyms of S. anguivi cited here and have elected not to select neotypes for these, we include them in synonymy based on the original descriptions.
We have chosen the sheet W-1889-0112166 as the lectotype of Solanum occidentale because it is the only specimen we or R. N. Lester found from the Lambert herbarium matching the description; Aylmer Bourke Lambert’s herbarium was sold in lots after his death and is widely distributed in many European herbaria (Miller 1970). It is not clear from the protologue where Dunal saw the specimen he cited as from “herb. Lambert”. It is likely Dunal saw the specimens he described as S. occidentale in Lambert’s herbarium when it was still in Lambert’s possession before it was broken up and distributed.