Iris foetidissima ex. Eastbourne, UK - seeds Calandstr, Leiden, NL 1 Dec 2010 08 Leo

On Distribution: Over the past few centuries, botanists seem to be shrinking the area which is commonly regarded as to where this plant is native. Ireland, Madeira, the Azores, the Canary Islands, the Netherlands and Switzerland have all been removed from the area where this plant is native. This same may also apply across a wider range. There is good evidence from France and northern Africa that this plant was cultivated to some extent in medieval and ancient times (an 'archaeophyte'), and even more interesting, there seems to be an odd correlation of this species with prehistoric sites in France (Chassagne [1956]; Robin, M. [1967]). This doesn't necessarily mean that the species was imported to France from elsewhere, but it may mean that its distribution and abundance have been positively influenced due to man for a long time.

Also of note is that formerly the distribution was believed to extend to Armenia and parts of the Russian Caucasus, where it was said to be particularly prevalent on the ancient graves of Muslims. It was theorized that the plant may have been a cultivated medicinal and was associated with the dead. Nonetheless, it is now known that these plants in question were in fact a distinct species; Iris musulmanica.

UK: Common in southern England, rarer in the Midlands, extending to York, Anglesey, Durham, Nottinghamshire. Also found on the Isles of Scilly and the Isle of Mann. Questionably native in Wales. Quite rare to absent in central Wales, but found relatively frequently in a band up the Welsh coast into southernmost coastal Scotland. The species is not native to Scotland and distribution in Scotland has quite recently expanded northward. In 1877 it was only known to have naturalized in two spots in East Lothian (Ormiston) and Fife (Dunfermline), south and north of Edinburgh, respectively, at present there have been sightings along the SE and SW coasts, around Glasgow, and even around the shores of the Moray Firth.

Channel Islands: Found on the islands of Alderney, Guernsey (along the coasts, common along the south coast, absent from the interior), Herm (throughout), Jethou (throughout) and Jersey (a few recent observations around St. Brelade, elsewhere absent).

France: Found throughout France, including Corsica, except the northeastern border regions with Belgium and Germany, and parts of the French Alps.

Italy: Found throughout all parts of Italy, including Sardinia and Sicily, but it is not found in the Aosta Valley in the far northwest alpine areas.

Malta: Very rare.

Spain: Also Gibraltar. Very common in the NE, but also found throughout Spain in a broad band along the entire Atlantic and Mediterranean coasts and along the Pyrenees. It is only absent from the regions of Madrid, Castilla La Mancha, Extremadura and southern Castile and Leon, and less common in the region of Valencia. Relatively common throughout Andalucia. Although I haven't found any evidence it doesn't occur on the Balearic Islands, I haven't found evidence it does.

Portugal: Found in a broad band along the coast from Galicia south to about Lisbon, somewhat further inland along river valleys, but otherwise absent from the interior. In the south, below Lisbon, it is absent from the coast until the city of Sines, but is present throughout the interior from Estremoz to the coast of the Gulf of Cadiz.

Tunisia: 'Flore de Tunisie' [2008], 'Flore Analytique et Synoptique de la Tunisie' [1954]

Algeria: It occurs in the Béjaïa Province (and probably other provinces). 'Flore de l'Algérie' [1884], 'Flore de l'Algérie et Catalogue des Plantes du Maroc' [1895], 'Flore de l'Afrique du Nord' [1959], 'Nouvelle Flore de l'Algérie' [1962].

Morocco: It occurs in the Tétouan Province (and possibly other regions). In the 'Catalogue des Plantes du Maroc' [1931], 'Flore de l'Afrique du Nord' [1959].

 

Unclear: Andorra

 

Established Neophyte (not necessarily invasive; but not native):

Azores Islands: Although the Flora Europaea [1980], GRIN, 'Flora of Macaronesia' [1985], D. Kramb at SIGNA [2004], the Kew Monocot Checklist [2006] and countless other sources consider this plant native to the Azores, the 'Listagem da Fauna e Flora Terrestres dos Açores' [2005], however, considers this an introduced plant. Despite this being the only work to consider it so, I follow these particular authors because this is the newest and most authoritative work I have read on the subject, and furthermore phytogeographically and historically it is to be expected this plant is not native to these islands. It occurs on the following islands now: Faial, Graciosa, São Miguel and Santa Maria.

Canary Islands: Introduced fide 'Flora of Macaronesia' [1985] & Kew [2006]. Tela Botanica, Flora Digital de Portugal and D. Kramb at SIGNA [2004] list it as occurring in the Canary Islands, but give no specifics about if it is native there. GRIN considers it native to the Canary Islands, but the source they use, 'Lista de Especies Silvestres de Canarias' [2004] states that it is certainly introduced. It occurs on the following islands: La Palma, Gran Canaria, and Tenerife.

Madeira: Introduced fide Kew [2006] & Flora of Madeira [1994].

Turkey: fide Kew, however it is not listed at all in the TUBIVES project. Davis's 'Flora of Turkey and the East Aegean Islands' [1965–1988] may mention it, however.

USA: fide PLANTS, SIGNA. "naturalized in woodlands north of San Francisco" Diane Whitehead [2008]. A weed in the East Bay area in the 'Weed Alerts! 2009' publication and in 'Annotated Checklist of the East Bay Flora' [1997]. The iris has naturalized in Sonoma, Contra Costa and Alameda counties, including natural areas such as Redwood Regional Park, Joaquin Miller Park or Sibley Volcanic Regional Preserve. Calflora gives observations in three additional neighbouring counties; Santa Cruz, San Mateo and Solano. These six counties are all in the Bay Area and all observations are from recent times (since the 1990's). According to Paghat's Garden it is categorized as an invasive weed in Nevada in the US, however it isn't listed as such by the Nevada Department of Agriculture or Defenders.org (nor can I find any reference of the plant having naturalized in Nevada at all); this is probably an error. On the other hand, it seems to have naturalized in King County near Seattle, in Washington state (Paghat writes from somewhere around here); it has been collected on Foster Island [2001, 2004] and Montlake [2005].

Canada: Naturalized on Prince Edward Island according to the 'Database of Canadian Vascular Plants' [2006] fide PLANTS.

Australia: Naturalized, possibly invasive in Tasmania fide Flora of Australia [1986] & Kew [2006]. The National Herbarium of New South Wales and the Australian National Herbarium in Canberra also has records of plants having naturalized on Mt Macedon in Midlands municipality, Victoria state.

New Zealand: Naturalized, common and invasive throughout New Zealand except Westland, Fiordland and Southland. It is increasing and considered a problematic exotic weed. The first mention of it having naturalized in New Zealand is from the 1890's near Nelson, but it wasn't until 1945 that a herbarium specimen was collected, or until 1958 that it incorporated in a flora of the region.

Ireland: Although traditionally believed to be a native of Ireland, the native status of this plant on the island has recently been called into question. Irish plants are now thought to be originally introduced and now cultivation relics or garden escapes. It can now be found throughout Ireland, including Northern Ireland.

 

Not Native:

Austria: EURISCO holds an accession collected in Austria. The plant is not native here, and it is unclear if the collection is from cultivated or naturalized plants.

Belgium: There are at least three very recent sightings of this plant in Flanders logged in the Waarneming.be database. The geotagged data would indicate, however, that all three sightings are of incidental garden escapes in or bordering urban garden situations, and can not be considered naturalized populations (if a plant reseeds in your garden, that doesn't mean it should be considered a sighting worthy of incorporating into the national flora).

The Netherlands: The distribution of this species in the Netherlands is quite interesting. Between the 1670's to perhaps the 1780-90's there was a single colony of this species near the hamlet of Vogelenzang, and in the 1830-40's a herbarium sample was collected on a dyke in the same area (between Leiden and Haarlem). Although initially it was considered possibly native, later works had begun to regard it as non-native by the beginning of the 19th century. In the 20th century probable garden escapes appeared in two spots on the (former) island of Voorne not far to the south. At the end of the 20th century it appears again in a park near the city of Rotterdam [1997] and far away in the province of Overijssel (a rather strange record from the Utah State University) [1998]. In the last decade there have been a number of reports of observations of this species in the Netherlands, all urban garden escapes or waifs: Castricum [2008]; Dordrecht [2008], the Hague [2009] and Bloemendaal [2009]. Another individual plant has been observed three times in a more naturalistic setting in the Noordhollands Duinreservaat near Egmond [2008, 2009, 2010]. All these observations were made in the provinces of North and South Holland.

Switzerland: The Flora Europaea lists this plant as a native of Switzerland, however the Swiss Web Flora does not list it, and the Kew Monocot Checklist follows that view. It is listed by the Flora Helvetica.

Ukraine: Cultivated specimens are mentioned in Komarov's 'Flora SSSR' [1935].

Other: There are curious reports of isolated plants of this species well to the east, far outside the normal range; in Greece, the Balkans, Pannonia, Armenia, Caucasus and even Afghanistan. Most of these reports can probably be disregarded as misidentifications, false taxonomy, or other errors, but perhaps here and there in Greece naturalized stands exist or may have existed as testaments to past cultivation as a medicinal or ornamental. The plants in the Caucasus growing on the graves of Muslims, which were once thought to be I. foetidissima, are now known to be a different species; I. musulmanica.

 

On Habitat: Although this species is said to occur to an altitude of 0-1400 in Italy, it is said to not occur above 500m in France. It is not at all a wetland species and can take quite dry soils, but it is best grown in moist yet well-drained soils. It prefers calcareous soils in nature, but can survive a different pH, and will in fact grow better in cultivation on rich loam of neutral pH. It seems to prefer open woodland and hedgerows as habitats, but it can persist in sunny open grassland. In France it is quite often found among the ruins of, or the parks around, old castles. Cows avoid eating it, but goats are said to eat it.

 

Done