Epidermal leaf characters of the Winteraceae

Leaf epidermal features (mostly studied in cuticular macerations) of 146 specimens, belonging to c. 33 species of all the 6 genera of the Winteraceae are described in detail. Typical for most representatives is the occurrence of alveolar material of cutinaceous nature overlying the cuticle proper, and usually occluding the stomata. Special attention is paid to the appearance, distribution and significance of this alveolar material. The taxonomic value of the characters described is discussed. All genera show an overlap with one or more genera in a varying number of leaf epidermal characters, so absolute diagnostic characters at the genus level are absent. It is also impossible to recognize distinct groups of genera. Exospermum and Belliolum are entirely within the leaf epidermal range of Bubbia. Drimys section Tasmannia and Bubbia perrieri take the most isolated positions within the family. Drimys piperita shows an enormous range of variation, which is further analysed using 85 specimens belonging to 38 of the 39 entities recognized by Vink. Of 12 entities more than one specimen was studied, affording the conclusion that in most entities the cuticular features are fairly constant, though some entities are very variable and certain characters are almost always variable at the level of the entity. For Drimys piperita as a whole a number of characters (shape and relative size of the stomata, shape of epidermal cells over midrib, undulations of anticlinal flanges, subdivisions of subsidiary cells) are mutually correlated and show, moreover, positive trends of correlation with the usual habitat of the entities. The glandular structures, typical for D. piperita, are described for the first time.