Collective type
The grouping of "small types" that are difficult to distinguish is called collective type . In biological systematics , the term aggregate (abbreviated: agg. ) Is also used for such closely related and difficult to distinguish species .
The division of plants and animals into clearly distinguishable species, which the systematists strive for, is often not clearly possible. Therefore, the boundaries between species, subspecies and variety are fluid and often depend on the personal judgment of the specialists working on these groups of plants or animals. In such an unclear or controversial situation, several manifestations of apparently closely related individuals can be grouped together (as a sort of solution to the problem).
Examples of this are the shapes of the blackberries ( Rubus fruticosus agg. ), The low-lying cinquefoil ( Potentilla anglica agg. ) Or the water cockfoot ( Ranunculus aquatilis agg. ).
The emergence of such flowing transitions of the forms is on the one hand a consequence of the differentiation in the course of the speciation , but can also be caused by hybridization .
See also
Individual evidence
- ^ A b c Peter Sitte, Hubert Ziegler, Friedrich Ehrendorfer, Andreas Bresinsky: Strasburger, textbook of botany. Gustav Fischer, Stuttgart, Jena, New York 1991, ISBN 3-437-20447-5 , p. 529.
- ↑ Rubus fruticosus agg. in FloraWeb
- ↑ Potentilla anglica agg. in FloraWeb
- ↑ Ranunculus aquatilis agg. in FloraWeb