| Foliar epicuticular wax structures/patterns can provide useful taxonomic characters. Use of the Scanning Electron Microscope to view the epicuticular wax layer of palm leaves allowed qualitative wax features to be readily characterized. These characters were used in a cladistic study of palms (Arecaceae), with an emphasis on the Coryphoideae. These characters were used in order to expand the number of phenotypic characters available for analysis.;It was found that epicuticular wax characters such as crusts/layers and rods do help support the monophyly of certain groups within the palms, e.g., the Coryphoideae and Borasseae. However, these characters are often quite homoplasious, as are many other morphological characters, and therefore, they should not be used alone in a cladistic study. Instead, they should be combined with numerous other phenotypic and/or molecular features (as was done here). In the analyses performed as part of this. investigation certain aspects of the current classification of Arecaceae are not supported. The monophyly of Ceroxyloideae, Arecoideae, and Calamoideae was called into question. The Coryphoideae are indicated as monophyletic, but the large tribe Corypheae is definitely non-monophyletic because Coryphinae and Borassaeae form a well supported clade. Analysis of combined data sets (e.g., epicuticular wax, vegetative anatomy, morphology, and DNA) are shown to provide increased resolution of infrafamilial clades. |
