One of the causes of instability in botanical nomenclature is found in that our predecessors did not verify the nomenclatural bearing of an unknown number of (often very rare) works. In PENNANT’s 4-volume ”Outlines of the Globe” (1800), a standard geographical work at its time (1) a chapter was found recently devoted to a ”Flora Indica”. The compiler had unintentionally made some name changes which remained unrecorded in scientific botany. Not long ago ROTHMALER unearthed many such works (2). It must be realized that, quite probably, many other works will be detected necessitating future unexpected and undesirable name changes. Our proposal is to exclude, onwards of 1951, for botanical nomenclature, all works which, up till that date, have not been used for purposes of priority. In other words, to declare these to be ”nomenclaturally extinct”.