in front of my house, it grows between stones
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I don't know what to say... the more I read in internet, the more I believe they are in fact synonymous, despite that Matthiola and Cheiranthus are 2 different droups ("genero")
Cheiranthus was lumped back into Erysimum a long time ago by SNOGERUP, S. 1967a. Studies in the Aegean Flora VIII. Erysimum sect. Cheiranthus. A. Taxonomy. Opera Botanica, 13:1-70 and SNOGERUP, S. 1967b. Studies in the Aegean Flora IX. Erysimum sect. Cheiranthus. B. Variation and evolution in the small-population system. Opera Botanica, 14:1-86
Erysimum and Matthiola are two very discrete genera. The correct name for your plant is Matthiola incana.
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