The Use of Cuticular Features in the Taxonomy of the Lauraceae

Abstract

The Lauraceae, with more than 2500 species in over 50 genera, and with the general lack of agreement in their recent classification, make an ideal canchdate for a global study based on leaf cuticles. A technique for preparing cuticles is presented, and three types of characters of use in such studies (cell form, slomatal complex, and special cell types) are discussed. Preliminary results demonstrate the utility of these cuticular characters in defining genera such as Endiandra and Beilschmiedia and in sorting out biogeograjihical anomalies, such as found in Caryodaphnopsis, wtiere the cuticles confirm placement of disjunct species within one genus. Potential challenges/problems posed by larger genera such as Litsea. Cryptocarya. Cinnamomum, Ocotea, and Nectandra are discussed.Two of the most recent classifications of the Lau-global generic revision of the Lauraceae, which folare those of Kostermans (1957) and Rohwer lows on from this project. Even in that study, the (Kubitzki et al., 1993). The former is based on his primary aim will be to place groups of species in own life-long studies, and the latter relies heavily consistently recognizable genera, and not necessaron Kostermans and on the w^ood anatomical studies ily to propose phylogenetic relationships (cladistic of Richter (1981), as well as including studies (pri-or otherwise). marily South American) by the author himself. The Cuticular studies of the Lauraceae are not novel, problems associated with these and other classifi-As early as 1926, Bandulska presented a study of cations of the Lauraceae are discussed by van der fossil and extant Lauraceae and described some Werff and Richter (1996, this issue). From that re-species of the former based on cuticular similarities view it is clear that further work is required to ar-to certain extant species. More recently. Hill (1986) rive at a satisfactory, or at least w idely acceptable, discussed those features of the cuticle that allowed classification of the family. Cuticular, and to a identification of Lauraceae, and placed the 12 spesmaller degree, leaf architectural studies form one cies of fossil Laurace found in the Eocene Nermodule in a multifaceted study of the generic de-riga deposit within the form genus Laurophyllum limitations of this family cuiTently in progress. based on these cuticular features. He made no at-The aim of this study is to analyze cuticular fea-tempt to place them relative to extant genera, tures for selected Lauraceae species whose generic Christophel and Rowett (in press) present descrippositions have been predetermined by others, and tions of leaf architecture and cuticles of all species in some cases questioned. At this time, no attempt of leafy Lauraceae found in Australia. They also has been made to use these features to confirm or present a dichotomous key to cuticular features that disprove the evolutionary position, or indeed the allows identification to the generic (or to a species **inonophyly" (sensu cladistics), of these groups of group within genus) level. Lauraceae....

Leaf surface characters applied to Lauraceae taxonomy in a Seasonal Forest of Southern Brazil

“…Rohwer growing on two environments, confirming the apparent genetic control of cell shape indicated by Cutler (1972). In summary, both the analysis (micro and macro) confirmed the family standard as found by other authors (Christophel et al, 1996;Marchiori, 1997;Marques, 2001;Boeger et al, 2004). According to Petzold (1907), the presence of epidermical cells with straight lines (predominant in the family) or sinuous anticlinal walls is an important character in differentiation of Lauraceae species.…”

Leaf and stem anatomy in eight Hypericum species (Clusiaceae)

“…1.epidermal epoxy replicas according to the LAROCHE (1982) protocol; 2.extraction of the cuticle according to the CHRISTOPHEL et al (1996) protocol; 3.SEM (Scanning Electron Microscope) observations. Fresh and permanent preparations were photographed using LM Leica DMLS, while digital images were obtained using a NIKON DS camera Head DS-Fi1.…”

Morphological and Anatomical Study of the leaves of Laurus nobilis L. (Lauraceae), growing in the Introduction of the Northern Caucasus region (Russia)

“…Stomatal apparatuses of paracytic type that is a characteristic diagnostic sign of family Lauraceae. [4][5][6] The epidermal cells in number of two are located to in parallel closing cells of a stomatal apparatus. Stomata are located often sufficiently.…”