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A TAXIMETRIC STUDY OF AN ANGIOSPERM FAMILY: GENERIC DELIMITATION IN THE CHRYSOBALANACEAE
Author(s) -
PRANCE G. T.,
ROGERS D. J.,
WHITE E.
Publication year - 1969
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1969.tb06518.x
Subject(s) - herbarium , confusion , biology , character (mathematics) , botany , mathematics , psychology , geometry , psychoanalysis
S ummary This is an account of how some taximetric techniques were used in a study of generic delimitation in the Hirtelleae, one of the two tribes of an Angiosperm family, the Chrysobalanaceae. It is probably the first account of a study in which the use of such techniques has formed part of an original monographic study of a sizable group of higher organisms above the species level. A preliminary study based on an examination of herbarium material of all 254 species suggested considerable departures from previously accepted generic concepts, chiefly involving the splitting of Parinari into four, possibly as many as eight, smaller, more clearly defined units. The character‐states of twenty‐one characters were recorded for all species (140) for which the material was sufficiently complete. These data were subjected to four taximetric analyses—two principal component analyses and two clustering analyses—which are described and discussed. All four clearly confirmed the heterogeneous nature of Parinari . Most of the tentative groupings were confirmed by all or most of these analyses. Accordingly the following segregates from Parinari are recognized: Bafodeya, Cyclandrophora, Kostermanthus, Exellodendron, Maranthes and Neocarya . For a few species the results obtained by the taximetric analyses are less unanimous; the reasons for this are discussed. Indecisive results were obtained for only two species. All four analyses yielded taxonomically meaningful results and provided insights into the taxonomic situation, though to different degrees. The Wirth, Estabrook and Rogers model gave the most useful results and displayed them in the most informative way. Since much confusion exists concerning the aims and methods of taximetrics, we have attempted to explain our own position. Rather than expect the reader to take on trust our statements concerning the contribution of taximetrics to our study, we have given a full account of the history of the problem and of our tentative taxonomic conclusions before the analyses were done, and have shown how they were confirmed or modified in the light of the results of the different methods.