© Shipunov A.B. Systema Angiospermarum [Electronic resource]. 1991—onwards.
Mode of access: http://herba.msu.ru/shipunov/ang/ang-en.htm

The classification of flowering plants

Current version:

• Classification, PDF (version information inside)
• What's new since 4.8, plain text
• Diagram of classification, in SVG
• Tree of families, in PDF
• References, in BibTeX
• Comparison (v.4.976) with other contemporary classifications

Previous versions:

• Version 5.1, PDF, used in: Shipunov A., Reveal J.L. Validation of subordinal names for "Systema Angiospermarum" // Phytotaxa. 2011. 16: 63-64
• Version 4.977, PDF, used in: Reveal J.L. Summary of recent systems of angiosperm classification // Kew Bulletin. 2011. 66: 1-44.
• Version 4.607, PDF, used in: Shipunov A.B. The system of flowering plants from synthetic point of view // Journal of General Biology. 2003. Vol. 64. N. 6. P. 501--510
• Short history of classification
• All other old versions (different file formats)

"Systema Angiospermarum" was the first classification of flowering plants which acquired molecular data, even before APGI. At the same time, it tried to inherit as much as possible from traditional classifications.

Basic principles

• The system is synthetic, it considers as much data as possible (e.g., from morphological, ultrastructural, geographical, biochemical and molecular fields). Since I am the single author of this classification, I always trying to maintain system up-to-date.
• System is fully hierarchical, there are most of ranks from family to classis (Angiospermae), namely suborders, orders and superorders. The non-traditional grouping as clades and "core" taxa are not used.
• The taxa are usually considered in most broad sense in the accordance with conception of "big orders" re-borned in the era of molecular taxonomy.
• The system is traditional: it means that paraphyletic taxa are widely (but not elsewhere) accepted.
  
  Further explanation needs here. I think that acception of paraphyly is not old-fashioned, it belongs to the of taxonomy as the expert science. Many authorities (Brummit, 2003; Grant, 2003; Rieppel, 2005) argued for paraphyly. The objections are often restricted to the fact that it is hard to take the description of paraphyly. But the consistent description is possible. I define paraphyletic taxa as taxa that include all common ancestors of given subgroups, but only some descendants of them. In his case, holophyletic taxa is the taxa include all common ancestors and all descendants; and polyphyletic taxa include only some ancestors and some descendants.
  Saying that, I accept paraphyletic taxa only in cases:
  1. When the comb-like tree exists: some neighbor branches are recognized as one taxon. This happens primarily because in such situations the different methods of analysis sometimes produced this grades as clades (the good example is Amborellaceae/Nymphaeaceae grade/clade). Here belong also the cases of bush-like trees.
  2. When the acceptance of paraphyletic taxa is the matter of tradition (Pan is not Homo, Aves are not Reptilia, Insecta are not Crustacea etc.). The taxonomy is for communicating between people, so we cannot ignore this reason.
  3. When the "ancestral diversity" exist: one largely indistinct group of subtaxa and one to several distinctive groups (like my Liliales and Arecales). This is the least feasible variant, because here is the biggest field for the speculations. But if the "ancestral" indistinct group and recognized distinct groups are supported morphologically, and at the same time all other (e.g., holophyletic) groupings do not have the good morphological support, this variant is acceptable.
  
  
• The structure of system is related with ideas about internal characteristics of taxa such as "centrality", "marginality" (sedis mutabilis, sed.m.), "fragility" and "adhesiveness" (both are status mutabilis, stat.m.). The most unstable taxa marked as "incertae sedis", or "i.s".
• The order of arrangement ("ordination") of taxa matters and reflects the similarities between the taxa. This is the reason why the system is beginning from Zingiberales and not from most primitive Nymphaeales (see also the diagram).
• The names of families are checked with the last work of Hoogland and Reveal (2005), the names of above ranks are traditional.

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