(First upload on November 21 2008. Last on November 4 2010. March 18 2017) [ 日本語 | English ]

Amaranthus retroflexus L.

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

Aogeitou (アオゲイトウ, 青鶏頭), redroot pigweed
Aobiyu (アオビユ), avoiding not to confusing with A. viridis, Aka-aobiyu (アカアオビユ)
Life form: annual forb, occasionally becoming 3 m in height
Origin: exotic to Japan from tropical America
Habitat: widespread weed on ruderal habitats, e.g., roadsdies

Field training on integrated environmental research (統合環境調査法実習)
HUSTEP: Plants and Plant communities in Japan (flora list)

Flower: monoecious

Amaranthus L. (ヒユ) in Japan

A. albus L. (ヒメシロビユ)
A. arenicola Johnst. (ヒメアオゲイトウ)
A. blitoides S. Wats. (イヌヒメシロビユ/アメリカビユ)
A. caudatus L. (ヒモゲイトウ)
A. cruentus L. (スギモリゲイトウ)
A. deflexus L. (ハイビユ), exotic to Japan (Hokkaido - Kyushu, flat and hill)
A. hybridus L. (ホソアオゲイトウ)
A. lividus L. var. ascendens (Lois.) Thell. (イヌビユ)
A. palmeri S. Wats. (オオホナガアオゲイトウ)
A. powellii S. Watson (ホナガアオゲイトウ/イガホビユ), south to Kyushu
A. retroflexus L. (アオゲイトウ)
A. spinosus L. (ハリビユ)
A. tricolor L.

ssp. tricolor (ハゲイトウ)
ssp. mangostanus (L.) Aellen (ヒユ)

A. viridis L. (ホナガイヌビユ/アオビユ)

Amaranthus retroflexus in Hokkaido

[1] a roadside at East Ward (N23/E1) in the city of Sapporo on August 30 2008. [2/3] a roadside at North Ward (N18/W3) in the city of Sapporo on June 13 2010. [4-6} at a roadside in N25/E3, East Ward, Sapporo, on August 19 2016.