Allium pendulinum Ten. (France, Italy) – An exceptional escape from cultivation or, more likely, a more or less established throw-out. Known from a single locality in Brugge where a small population persists since 2014 (initially erroneously ascribed to A. paradoxum) in a grassy bank alongside a former railway track, close to a garden center. In this locality it grows along with several other species of Allium, including A. triquetrum and A. roseum.
Allium pendulinum is very characteristic in having triquetrous stems and inflorescences that consist of flowers only. These features are shared with A. triquetrum, a closely related species. A. pendulinum is sometimes considered a variety or subspecies of the latter. It is distinguished by its much smaller stellate flowers with patent tepals, shorter stems and longer pedicels.
Selected literature:
Cela Renzoni G. & Garbari F. (1970) Il genere Allium L. in Italia: I. Allium pendulinum Ten. et A. triquetrum L. G. Bot. Ital. 104: 61-73.