[senacion anglicized form of med.L. senaciōn-em, for L. seneciōn-em groundsel, sencion. 1526Grete Herball ccccviii. (1529) Y ij b, Whan receptes expresseth Senacions in the plurell nombre it is to wyte cresses. But yf senacion be wryten in the synguler nombre, it is an other herbe.]