It is assumed that the Wallflower Erysimum cheiri, which is known only as an ornamental plant,
has been breeded already in the Roman times out of Erysimum species from the Eastern Mediterranean and Asia Minor
as e.g. Erysimum corinthium WETTST. and Erysimum senoneri WETTST.
In the walls of Heidelberg Castle relatively primordial yellow-flowered forms have been preserved,
which converge towards the parent species again.
These differ not only by the lighter flower color, but e.g. also by smaller plant height and shorter leaf length
from the orange to red flowered forms currently offered in garden trade or some ten years old forms still available in cottage gardens.
Unfortunately in the Heidelberg Castle often renovations are destroying Wallflower sites.
The plants which are cultivated in a monastery on the Greek island of Samos seem to belong to a similarly old form.
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