WALL RUE / Asplenium ruta-muraria

One sometimes finds cases of using rue-fern instead of rue itself in ritual. It could be used, for instance, by a jilted girl, who could wait in the church porch while the man was being married to someone else. She could then throw a handful of wall-rue at him when they came out, with “May you rue this day as long as you live” (Leather) (see also RUE).