VII - The wood anatomy of the family Sterculiaceae

The group Malvales is moderately well defined, both taxonomically and in the anatomy of the wood, but, to judge by the frequency with which the limits of the families are constantly being revised, its division into families and subfamilies is still a matter of some difficulty to taxonomists. A similar state of affairs exists in regard to the wood, for, although it is comparatively easy to recognize a specimen as one of the Malvales, it is often extremely difficult to decide to which family it belongs. This is possibly due in large part to faults in the systematic grouping, and the present investigation was undertaken to find out whether the groups suggested by the wood anatomy can be used to clarify the taxonomic position. In one family in particular, the Sterculiaceae, the wood anatomy suggests a heterogeneous group that needs revising, and this family has therefore been selected for detailed study. Two aims have been kept in view: the first, to find out how far the wood anatomy is in agreement with the present taxonomic classification, and what changes it suggests; the second, to try to ascertain which features in the wood are peculiar to a family, and imply relationship, and which are to be encountered in unrelated families, and represent stages in phylogenetic development.