Sisyrinchium californicum

Sisyrinchium californicum (Ker Gawler) Dryander (incl. S. brachypus (E.P. Bicknell) J.K. Henry) (western N Am.) – A very rare and probably ephemeral alien. A single individual was first observed on bare sand in a municipal storage area in Lommel in 2014, possibly from garden debris. Since 2019 a small population (ca. five individuals) persists in a nature reserve in Itterbeek.

This species is naturalized in the British Isles since the end of the 19th century (Parent 1980) and appears to be increasing, especially on lake shores, in marshy meadows and in other damp, grassy places. It reproduces by seed and some populations are very large (Online Atlas of the British and Irish Flora at: http://www.brc.ac.uk/plantatlas/index.php?q=node/2615). In more recent times it has repeatedly been recorded in the Netherlands as well (see: http://waarneming.nl/soort/view/26608). At least in some of its localities there, it looks perfectly established. It is often found in valuable habitats and is potentially invasive (van Walsum 2021).

Sisyrinchium californicum is a rather variable species. Many segregates have been described but all these are now comprised in a broadly circumscribed S. californicum (Cholewa & Henderson 2002). This also holds true for S. brachypus to which, according to Parent (1980), all plants from the British Isles as well as most horticultural plants belong.

Selected literature:


Bicknell E.P. (1900) Studies in Sisyrinchium-VIII: Sisyrinchium Californicum and Related Species of the Neglected Genus Hydastylus. Bulletin of the Torrey Botanical Club 27(7): 373-387. [available online at: https://archive.org/details/jstor-2478249]

Cholewa A.F. & Henderson D.M. (2002) Sisyrinchium. In: Flora of North America Editorial Committee (eds.), Flora of North America, vol. 26. Oxford University Press, New York-Oxford: 351-371. [available online at: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=130515]

Davis T.A.W. (1975) Yellow-eyed grass on Skomer Island, Pembrokeshire. Nat. Wales 14(4): 273.

Ingram R. (1967) On the identity of the Irish populations of Sisyrinchium. Watsonia 6: 283-289.

Lakshmanan K.K. & Philip V.J. (1971) A contribution to the embryology of Iridaceae. Proc. Indian Acad. Sci., B 73(3): 110-116.

Parent G.H. (1980) Le genre Sisyrinchium L. (Iridaceae) en Europe. Un bilan provisoire. Lejeunia 99: 40 p.

van Walsum S. (2021) Gele bieslelie. Kijk op Exoten 34: 10-11.  [available online at: https://www.ravon.nl/Portals/2/Bestanden/Publicaties/Nieuwsbrieven/KijkO...

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith