Campanulaceae work has showed that there are no characters by which distinctly could enable generic circumscription. Some have, argued for instance that in the Nothern Hemisphere, North American studies, characters (pollen and seedcoat sculpturing) used for family or subfamily circumscription,could be used for generic circumscription.
Is it possible to do that for the Southern Hemisphere bellflowers? In South Africa as well, much work has been done on the family but mostly is outdated in terms of generic circumscriptions and needs urgent revision.
I am currrently busy with the revision of the subgenus afrotrachelium. My intentions are to find new set of characters that will determine the fate of the subgenus; My question is does Prismatocarpus subgenus afrotrachelium deserve a genus status?
The characters thus discovered in this subgenus could be used to for generic circumscription. I have no intentions of using molecular phylogenetics since according to Cupido et al. (2011) and Cupido (2009) there is incongruency with the molecular phylogenetic trees with the trees for morphological characters, together with the primary character of capsule dehiscence.
It is hardly meaningful - and certainly very difficult and often impossible to achieve - to try to a specific character or set of characters for recognition of units at a certain taxonomic level. Basically, what systematists do today is to recognize groups based on molecular (DNA-)data, making sure that formally recognized units are monophyletic and if at all possible, recognizable by one or more morphological characters (more accurately: character states). These are rarely unique, so often a (unique!) combination of non-unique states will have to do. One could argue that one should keep merging genera (or other taxa at a certain level until well supported, monophyletic and recognizable groups remain, and only those should bear a name. In this case, how about merging all wahlenbergioids into Wahlenbergia (the ones with apical capsule dehiscence along with nested offshoot genera, e.g. the insular Nesocodon etc. and temperate Cape province genera such as Roella etc.)?
Mats H. G. Gustafsson
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Thanks Mats,
The issue with Campanulaceae as indicated from the studies done by Cupido (2009) is the incongruity between the trees (phylogenetic) for morphological characters and the molecular phylogenetic trees. Also the characters seem to be fine at the family level but at the generic level but do not hold taxonomic importance. Now I need to find out new characters that have never been explored, however, even them will not be enough until I compare with the molecular data.
I just wanted to find out if there has been some other characters explored below family and generic levels, such as tribe, subtribe or subgenera within the Campanulaceae family. I hope my question is clear?
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