Thanks for the click! Did you figure out this week’s “I Spy in the Sea to Sky…”? Chances are, that if you’ve floated down the River of Golden Dreams in a canoe, or in an orange Explorer 200, you’ve seen this invasive species, but never thought anything of it.
Yellow Flag Iris is an invasive species in the Sea to Sky which is currently flowering. Yellow Flag Iris flowers from April to July, and in the past it has been spotted along the shorelines of the River of Golden Dreams and Green Lake in Whistler.
Identifying Yellow Flag Iris can be tricky as it is often confused with Common Bulrush, also known as Common Cattail, which is a non-invasive aquatic plant. Some key identifiers of Yellow Flag Iris include the leaves, which fan out from the flattened base of the stem, and the 3 fully yellow petals that form the flower. A fun fact about Yellow Flag Iris is that its the only member of the iris family that possesses an entirely yellow flower.
It spreads by floating seeds and creeping rhizomes (plant roots), slowly choking out wetlands and blocking water flow. Yellow Flag Iris grows in dense stands and displaces native plants and animals, which ultimately alters the ecosystem. It is toxic to humans and animals, causing skin irritation and severe gastrointestinal distress, so we don’t recommend removing it by yourself!
If you are determined to remove it on your own, make sure to dig out the rhizomes to their full depth (30cm), including the surrounding area (about 30cm out). Be warned that Yellow Flag Iris is HEAVY, and can be difficult to lift or move once removed. Do not compost, and wear gloves to prevent contact with toxic resins.
For more information on identifying Yellow Flag Iris and removal methods, click here.