(First upload on June 29 2014. Last on June 2 2019) [ 日本語 | English ]

Iris pseudacorus L.

Mount Usu / Sarobetsu post-mined peatland
From left: Crater basin in 1986 and 2006. Cottongrass / Daylily

Iris L. (アヤメ)
Iris ensata Thunb. (s.l.)
Kisyoubu (キショウブ, 黄菖蒲), yellow iris
Lifeform: perennial forb, forming extensive colonies
Distribution: native to East Asia and Europe (exotic to Japan, cultivated in Meiji Era and escaped thereafter)

caution-needed invasive alien species
Hokkaido Blue List: A2

Habitat: wetlands (湿原), such as paddy fields and streamsides
Use: gardening, biotope (controversial due to the biological invasion)
Varieties (cultivars)
Roy Davidson, Variegata, etc. → commonly used for gardening

Iris pseudacorus in Hokkaido

Iris1 Iris2 Iris3
Iris4 Iris5
[1] apparently escpaed from elsewhere and well-established in the Sosei River at N10, Sapporo, on June 2 2014. [2/3] at a pond in garden of Hokkaido Prefectural Government, Sapporo, on May 22 2014. [4/5]