(First upload on February 17 2010. Last on January 17 2019) [ 日本語 | English ]

Polygonum arenastrum Jord. ex Boreau

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

Polygonum L. (タデ)
Haimichiyanagi (ハイミチヤナギ, 這道柳), oval-leaf knotweed
Kogomemichiyanagi (コゴメミチヤナギ)
Lifeform: weedy, summmer-annual forb
Distribution: widespread in the northern hemisphere (exotic to Japan)

Hokkaido Blue List: A3

Habitat: common on roadsides and open fields

HUSTEP: Plants and Plant communities in Japan (flora list)


Polygonum aequale Lindm.
Polygonum aviculare L. (ミチヤナギ) var. arenastrum (Jord. ex Boreau) Rouy, often used


Polygonum arenastrum in Hokkaido

ST1s ST2 ST3
[1/2] in N28/E4, East Ward, on August 30 2009. [3] in an openland along Ishikari Coast, where a wind power will be established, on September 3 2015. [4/5] on a paved road in N28/E2, East Ward, Sapporo, on October 1 2018. [6] on an unpaved parking lot, N26/E2, East Ward, Sapporo, on August 19 2016. Record: at a wasteland in N28/E4, East Ward, on August 30 2009; in the former sport ground of an elementary school in the city of Muroran on September 14 2015. The school was closed in the last year.