Sui generis
In sociology, the "sui generis" is what has been externalized, then internalized in the overall public and becomes a part of society that simply exists in its construct. It is not something that is not thought to have been created, because it is imbedded in everyone's way of thinking and being. Instances include the idea of love, or going to school, or clothing belonging to a specific gender. These examples are "sui generis" for they simply exist in society and are widely accepted without thoughts of where they come from or how they were created.
Senecio eboracensis
The science of this plant is that it is a hybrid species whose parents are the self-incompatible and promiscuous Sicilian "Senecio squalidus" (also known as Oxford ragwort) and the self-compatible and tenacious "Senecio vulgaris" (also known as Common groundsel). Like "S. vulgaris", "S. eboracensis" is self-compatible, however, it shows little or no natural crossing with its parent species, and is therefore reproductively isolated, indicating that strong breed barriers exist between this new hybrid and its parents.
It is thought to have resulted from a backcrossing of the F1 hybrid of its parents to "S. vulgaris". "S. vulgaris" is native to Britain, while "S. squalidus" was introduced from Sicily in the early 18th century; therefore, "S. eboracensis" has speciated from those two species within the last 300 years.