Solanum nava
Not known
Endemic to the Canary Islands, only known from Tenerife in laurisylva (laurel) forest at low elevations; probably introduced to the Azores.
Solanum nava is a member of the Normania clade of Bohs (2005), and was previously recognised as one of two species (the other being S. trisectum) of the endemic Macaronesian genus Normania. This species has not yet been included in molecular analyses.
Dunal, M.F. 1852. Solanaceae.
Pp. 1-690 in A. P. DeCandolle (ed.), Prodromus Systematis Naturalis Regni Vegetabilis 13(1). Victoris Masson, Paris, France.
Bitter, G. 1912. Solana nova vel minus cognita II.
Repert. Spec. Nov. Regni Veg. 11: 1-18.
Bitter, G. 1917. Solana Africana II.
Bot. Jahrb. Syst. 54: 416-506.
León Arencibia, M.C., I. La Serna Ramos & W. Wildpret de la Torre 1984. Contribución a la tipificación de endemismos Canrias descritos por Webb y Berthelot. II.
Vieraea 13: 17-26.
Francisco-Ortega, J., J.G. Hawkes, R.N. Lester & J.R. Acebes-Ginovés 1993. Normania, an endemic Macaronesian genus distinct from Solanum (Solanaceae).
Plant. Syst. Evol. 185: 189-205.
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.
Solanum nava is an extremely rare plant, and was thought to be extinct until collected in 1973 and 1982 in the laurel forests of Taborno on the Anaga Peninsula of the island of Tenerife (Francisco-Ortega et al. 1993). Considered by Dunal (1852) as a member of his subsection Tuberarium (potatoes and relatives), S. nava and its close relative S. trisectum of Madeira were considered as a distinct section of Solanum by Bitter (1912, 1917). Francisco-Ortega et al. (1993) recognised these two species as the genus Normania, differentiated from Solanum on the basis of the horned anthers, zygomorphic flowers, and distinct seed and pollen morphology. Molecular studies indicate that these species (and their close relative S. herculeum, previously recognised as the genus Triguera) form a distinct clade within a larger, monophyletic Solanum (Bohs & Olmstead, 2001).
Solanum nava can be distinguished from S. trisectum by its ovate leaves with cordate bases, its less glandular parts and its black anthers with horns about halfway from the base. The species is endemic to the island of Tenerife in the Canary Islands; the specimen from the island of São Miguel in the Azores is likely to be an introduction (J.R. Press, pers. comm.). Its restricted range and lack of known populations makes it of considerable conservation concern on a global scale. Solanum nava can be given a preliminary conservation assessment of Endangered (EN), using the IUCN Red List criteria. The instability of populations of this species (Francisco-Ortega et al. 1993) will make conservation difficult.
In lectotypifying Solanum nava, León Arencibia et al. (1984) selected what they considered the original of several sheets labelled “Solanaceae No. 9” in FI, and that which best matched the plate accompanying the protologue. The lectotype sheet bears an original label stating “9 Solanum: planta Rarissima – Invem tantum ad scaturigenum Caidero de Coruña dietano in convalle altâ sub montibus Juncillo suprá sicum Tenteniguada”. The sheet is pictured as Figure 8 in León Areneibia et al. (1984).