REDDISH PURPLE PIGMENTS IN SECONDARY PERIDERM TISSUES OF WESTERN NORTH AMERICAN CONIFERS

A new class of non-anthocyanic reddish purple pigments has been found in secondary periderm tissues of coniferous bark by application of a thin-layer chromatographic technique developed for the purpose. Contrary to established belief, these pigments referred to also as phlobaphenes, consist not of single substances, but of mixtures of several distinct pigments. Western red cedar (Thuja plicata Donn.) contains at least eight of these new pigments, amabilis fir (Abies amabilis (Dougl.) Forbes) at least six, and western hemlock (Tsuga heterophylla (Raf.) Sarg.) at least nine. Moreover, contrary to the current views, the pigments in the bark of the three species studied differ from one another. Although the exact identity of these pigments remains to be ascertained, the techniques permit qualitative comparisons of the pigments in different species. It is further established that these pigments do not occur in normal primary periderm of the bark. © 1969.