A very helpful note from Dr Daniel Kelly from the Botany Department at Trinity College on the location of R cathartica in Ireland. This otherwise very attractive shrub/small tree is a management nuisance in the Midwest, especially prevalent in the Chicago Wilderness region.
Dr Kelly reports from the 'Flora of Connemara & the Burren': "Woods, scrub, river-banks, rocky lake-shores and the margins of turloughs. Locally frequent on the limestone; very rare elsewhere..." "... Very frequent ... from near Oughterard to 3 km N. of Galway ... Locally abundant by the S. shore of L. Mask. Sparingly on the shore of L. Corrib in the grounds of Ashford Castle, and frequent on several of the islands."
It will be nice to see this plant in circumstances that do not provoke indignation and death-threats!