Solanum stramoniifolium
2n = ploidy missing =24 voucher missing =
A lowland species usually encountered between 0 and 600 m, occurring naturally in savannas, ecotones between forest and savanna, forest openings, and along riverbanks, in open sun or partial shade; tolerant of diverse soil types from rich to relatively sterile sandy soils, usually on well drained substrata and not ordinarily found in swampy situations. Common as a weed in man-made clearings, pastures, fields, secondary thickets, trailsides, roadsides, and about human habitations. Extending from lowlands east of the Andes in Colombia, Ecuador, and Peru east across the northern Amazon Basin, the upper Orinoco Basin, and lower elevations of the Guyana Shield to eastern Venezuela and Belém, Brazil. Occasionally cultivated in Colombia and Peru for the edible fruits. Sporadically adventive elsewhere in the tropics.
Solanum stramoniifolium belongs to the Leptostemonum clade of Solanum (Bohs, 2005). Within Leptostemonum, it belongs to the Lasiocarpa clade, a monophyletic group that includes most of the species traditionally recognized in Solanum section Lasiocarpa Dunal (Whalen et al., 1981; the S. quitoense species group of Whalen, 1984; Levin et al., 2006). Within this clade, chloroplast sequences from the trnT-F region indicate that S. stramoniifolium belongs to a clade that also includes S. sessiliflorum and S. pectinatum (Bohs, 2004). However, nuclear waxy sequence data do not support this relationship and fail to identify close relatives to S. stramoniifolium within the Lasiocarpa clade (Bohs, unpublished data).
Schultes, R.E., & R. Romero-Castañeda 1962. Edible fruits of Solanum in Colombia.
Botanical Museum Leaflets 19: 235-286.
Macbride, J.F. 1962. Solanaceae.
Flora of Peru. Field Mus. Nat. Hist., Bot. Ser. 13(5B): 1-267.
D’Arcy, W.G. 1970. Jacquin names, some notes on their typification.
Taxon 19: 544–560.
Whalen, M.D., D.E. Costich & C.B. Heiser, Jr. 1981. Taxonomy of Solanum section Lasiocarpa.
Gentes Herb. 12: 41-129.
Whalen, M.D. 1984. Conspectus of species groups in Solanum subgenus Leptostemonum.
Gentes Herbarum 12 (4): 179-282.
Bohs, L. 2004. A chloroplast DNA phylogeny of Solanum section Lasiocarpa (Solanaceae).
Syst. Bot. 29: 177-187.
Bohs, L. 2005. Major clades in Solanum based on ndhF sequences.
Pp. 27-49 in R. C. Keating, V. C. Hollowell, & T. B. Croat (eds.), A festschrift for William G. D’Arcy: the legacy of a taxonomist. Monographs in Systematic Botany from the Missouri Botanical Garden, Vol. 104. Missouri Botanical Garden Press, St. Louis.
Levin, R.A., N.R. Myers, & L. Bohs 2006. Phylogenetic relationships among the "spiny" solanums (Solanum subgenus Leptostemonum).
Amer. J. Bot. 93: 157-169.
nuclear ITS sequence: GenBank AY263465 (voucher: Whalen & Salick 860, BH) nuclear waxy (GBSSI) sequence: GenBank AY562970 (voucher: Whalen & Salick 860, BH) chloroplast ndhF sequence: GanBank AF500863 (voucher: Whalen & Salick 860, BH) http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=nucleotide&val=27463509 chloroplast trnS-G sequence: GenBank AY555476 (voucher: Pickersgill 154, IND) chloroplast trnT-F sequence: GenBank AY266263 (voucher: Whalen & Salick 860, BH) http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=nucleotide&val=33355764 chloroplast trnT-F sequence: GenBank AY266244 (voucher: Pickersgill 154, IND) http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=nucleotide&val=33355745
Commentary taken from Whalen et al. (1981):
Solanum stramoniifolium is a phylogenetically isolated species within section Lasiocarpa. Its truncate calyx and small, bright red berries, glabrous at maturity, are unique in the group. Within section Lasiocarpa, a distant relationship with S. sessiliflorum might be suggested on the basis of similarity in structure of trichomes on stems and berries. Cauline stellae in both species have reduced midpoints and lateral rays oriented in a horizontal plane. Those of the fruits also have shorter midpoints than are found in other species and have numerous, short lateral rays distributed densely along the trichome stalks. The large, broad-based, sparsely distributed cauline prickles of both species may also reflect a relationship. In many other respects, S. stramoniifolium and S. sessiliflorum are very different. The latter species bears stellate hairs with elongate midpoints on upper leaf surfaces and has well-developed calyx lobes and large fruits.
Solanum stramoniifolium displays a striking pattern of geographical variation. Most specimens from the western Amazon Basin are unarmed (except the earliest growth). Many of the same collections have membranous leaves, sparsely puberulent or glabrous above, and relatively large berries. The distribution of this western race corresponds to the regions in which the species is used and occasionally cultivated by man. The somewhat larger fruits and lack of prickles suggest a history of human selection. Some recent authors have recognized the western race as a species or group of species distinct from S. stramoniifolium (Macbride 1962; Schultes and Romero-Castañeda 1962). Whalen et al. (1981) did not feel that this interpretation is warranted, because distinguishing characters are not entirely correlated in their occurrence, and broad geographic intergradation is observed in some of them. They chose to recognize the races as taxonomic varieties.
Note added by Bohs (2006):
The correct compound form of the specific epithet is “stramoniifolium.” Thus, alternative spellings such as that in Whalen et al. (1981; as “stramonifolium”) should be automatically corrected under Article 60.8 of the ICBN.