The problems of distinguishing Pinus patula Schiede and Deppe ssp. tecunumanii (Eguiluz and Perry) Styles from P. oocarpa Schiede in mixed natural stands in Central America prompted this taxonomic investigation which examines relationships within and between provenances of the two taxa. Orthodox taxonomic descriptions are shown to be unsatisfactory in aiding discrimination between them. A pilot study was planned using 200 trees from five populations of 20 trees from each of the two taxa. Linear discriminant and canonical variable analyses of fifteen needle and cone morphological characters (variables) were carried out. Seven variables were found to contribute significantly to a discriminant function which identified trees as belonging to one or other of the two taxa with only 3010 mis-classified. A second discriminant function which used only easily measurable (non-microscopic) variables was calculated; this separated the two taxa with the proportion mis-classified increasing to 9.5010. Canonical variable analysis using the same variables as in the first discriminant function confirmed the presence of two classes (species) and showed that P. patula ssp. tecunumanii is a much more variable taxon than P. oocarpa. Data from further provenances of disputed identity were then included in the analyses. These showed that the following provenances in the CFI International Provenance Trials of P. oocarpa are in fact P. patula ssp. tecunumanii: Mountain Pine Ridge, Belize; San Rafael, 'Yucul and Las Camelias, Nicaragua. Mexican provenances of P. oocarpa to which the varietal name ochoterenae Martinez is attached are also clearly classified as P. patula ssp. tecunumanii. Finally analysis of data from two provenances of P. patula are presented. This suggests that the citation of the Tecun Uman Pine as being a subspecies of P. patula is correct.
Mccarter, P.S.; Birks, J.S. Pinus patula Sub-species tecunumanii: the application of numerical techniques to some problems of its taxonomy. Commonwealth Forestry Review (1985) 64 (2) 117-132.