Solanaceae Studies II: Typification of Subdivisions of Solanum

Abstract

A useful step in the study and identification of plants is the assembling of species into infrageneric groups, and this is especially so in the genus Solanum. In this genus the great number and diversity of species discourages study, yet many groups can readily be assembled within the genus which have every appearance of being natural and distinct from one another. In the past, many groups were formally recognised with a considerable redundance of names. To bring some order to the surfeit of names, names of subdivisions of the genus are reviewed here with respect to their rank, validity of publication and typification; and to clarify the relationships of taxa to one another, a provisional conspectus is presented, not as a reworking of the taxonomy of the genus so much as a framework from which nomenclatural values can be seen. The desirable sequel, designation of the limits of taxa and keys to distinguish them, must await later efforts. The present paper is one necessary step in making the parts of this important genus more accessible to study. The literature search was careful and perhaps cxhaustive, but there is the usual possibility of unexpected discoveries altering the nomenclature presented here, and in the future, especially when the flora of South America is better understood, there will be additions to the generic subdivisions noted here. Help was sought from other workers: Susan M. Coles, University of Birmingham, chose the lectotype for section Cryptocarpum; R. M. Polhill, Royal Botanic Gardens, Kew, chose lectotypes for African taxa, and Don Ugent, University of Southern Illinois, Carbondale, chose the lectotype for Regmandra. Roger Polhill also helped in checking bibliographic references, and R. K. Brummit, Royal Botanic Gardens, Kew, uncovered several names overlooked by the writer. In addition to the above who helped directly in the study, the late C. V. Morton, Smithsonian Institution, Washington, and W. D. Margadant, Biohistorisch Institut der Rijksuniversiteit, Utrecht, provided advice on particular aspects of the project. Assistance from these people is gratefully acknowledged: the writer at the same time takes full responsibility for all choices and decisions not clearly attributed to others. The alphabetical listing of names indicates the first rank, place, and date of publication as well as the validity of each name published in the genus Solanum between the ranks of genus and This is followed by subsequent changes of rank and finally by the type Holotypes and automatic choices under Art. 22 of the Code are indicated as Type species. Other choices are Lectotype species, and if the choice is not first made here by the writer, source of the choice follows in square brackets.