As much on the general subject of synonymy as it is relating to 'Baron Chaurand' is what the Ketten catalog of 1901, p. 101, has to say under heading 'Baron de Bonstetten'; to wit, the entry begins by stating that Bonstetten "= Boncenne (Liabaud 65)"--which we moderns reading it would understand as we being told that 'Baron de Bonstetten' and 'Monsieur Boncenne' are synonyms--but then goes on to state that 'Baron de Bonstetten' and 'Baron Chaurand' are both seedlings of ("issues de") 'Monsieur Boncenne', "resembling it very much." Clearly, synonymy and "=" in the era are to be understood as being as likely to simply mean "lookalikes" or even "near lookalikes" as much as being true "identical same plant" synonyms. Perhaps the idea was from the exhibition tables, where lone display blossoms of various varieties could under those exhibition conditions be difficult to distinguish (while, on the plant with blossoms in other states of expansion, and on plants which would differ in habit and/or behavior, it would be easier to tell the difference).