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Yellow iris is an introduced invasive species that is native to Europe, western Asia and northwest Africa. Outside its native range, it is a significant invader in freshwater and brackish cattail marshes and spreads in marshes and adjacent areas by underground rhizomes and seeds. In North America, it is now found in many US states (AL, AR, CA, CT, DC, DE, FL, GA, ID, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, MT, NC, NE, NH, NJ, NV, NY, OH, OR, PA, RI, SC, TN, TX, UT, VA, VT, WA, WI, WV) and Canadian provinces (BC, MB, NB, NF, NS, ON, PE, QC) (USDA 2010). In BC, it is found in the southern part of the province, where it occurs in marshes, ditches, sloughs, streambank and pond edges. It is a favourite plant in water gardens and artificial ponds because of its bright yellow flowers.
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General: Perennial herb from a thick rhizome; flowering stems usually simple, sometimes branched, 50-150 cm tall.
Leaves: Mostly basal, linear-lanceolate, 50-90 cm long, 1-3 cm wide, entire, the tips long-pointed.
Flowers: Inflorescence of (2) 4 to 12 showy flowers on stout, 2- to 5-cm long stalks; flowers pale to deep yellow, the tubes flared above, 1-1.5 cm long; petals erect, narrowed at the middle, about 2-3 cm long, 4-8 mm wide, the bracts herbaceous, the margins translucent; sepals broadly rounded, 5-7.5 cm long, 2-3 cm wide, bent back; style branches 2-2.5 cm long, the crests less than 1/2 as long; stigmas rounded.
Fruits: Capsules, cylindrical, 4-8 cm long; seeds numerous.
This species is listed by the Greater Vancouver Invasive Plant Council of the twelve most problematic species in the Vancouver region. For further information about control of this species, visit their web site. It is also listed as one of the top fourteen species of concern by the Coastal Invasive Plant Committee. Visit their web site.
Ecological Framework for Iris pseudacorus
The table below shows the species-specific information calculated from original data (BEC database) provided by the BC Ministry of Forests and Range. (Updated August, 2013)
Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2020. E-Flora BC:
Electronic Atlas of the Plants of British Columbia [eflora.bc.ca]. Lab for
Advanced Spatial Analysis, Department of Geography, University of British
Columbia, Vancouver. [Accessed:
2021-01-19 8:14:26 PM
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