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Comparative Vegetative Anatomy And Systematics Of Oncidiinae (Maxillarieae, Orchidaceae), William Louis Stern, Barbara S. Carlsward
Comparative Vegetative Anatomy And Systematics Of Oncidiinae (Maxillarieae, Orchidaceae), William Louis Stern, Barbara S. Carlsward
Barbara S. Carlsward
Subtribe Oncidiinae comprises a vegetatively heterogeneous assemblage of species that has persistently been incapable of organization. Anatomy was considered to be a possible means to resolve the perplexity of relationships amongst the constituent taxa. The consistent occurrence of a foliar hypodermis, homogeneous mesophyll, conical silica bodies in stegmata, and ubiquitous fibre bundles in leaves provides a matrix for linking the taxa, as do the parenchymatous pith and O-thickened endodermal cell walls in roots. However, the strict consensus of the 40 genera studied was completely unresolved, suggesting that vegetative characters alone are insufficient to assess the relationships amongst these taxa, a …
Comparative Vegetative Anatomy And Systematics Of The Angraecoids (Vandeae, Orchidaceae) With An Emphasis On The Leafless Habit, Barbara S. Carlsward, William Louis Stern, Benny Bytebier
Comparative Vegetative Anatomy And Systematics Of The Angraecoids (Vandeae, Orchidaceae) With An Emphasis On The Leafless Habit, Barbara S. Carlsward, William Louis Stern, Benny Bytebier
Barbara S. Carlsward
The vegetative anatomy and morphology of 142 species of the angraecoid orchids (Angraecinae + Aerangidinae) and 18 species of Aeridinae were examined using light and scanning electron microscopy. Leafless members of Vandeae were of particular interest because of their unique growth habit. Leafy and leafless members of Angraecinae and Aerangidinae were examined and compared with specimens of Aeridinae. Vandeae were homogeneous in both leaf and root anatomy. A foliar hypodermis and fibre bundles were generally absent. Stegmata with spherical silica bodies were found associated with sclerenchyma and restricted to leaves in almost all specimens examined. Distinct inner tangential wall thickenings …