(First upload on October 29 2012. Last on March 25 2021) [ 日本語 | English ]

Equisetum fluviatile L.

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

Equisetaceae Michx. ex DC (トクサ)
Mizudokusa (ミズドクサ, 水木賊/水砥草), water horsetail/swamp horsetail
Mizusugina (ミズスギナ, 水杉菜)
Lifeform: perennial summergreen fern < 150 cm high ↔ E. hyemale = evergreen

Stems are collasped when we touch even gently (comments from Sato)

Distribution: the temperate Northern Hemisphere, including northern Japan
Habitat: dense colonies in shallow water

Field training on integrated environmental research (統合環境調査法実習) (fauna and flora 種リスト)

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

Branch: diverse length, i.e., none - short - long
Stem: smooth surface
Chromosome number: n = 108 (Sorsa 1963)

Equisetum limosum L. (common scientific name in Japan)
Equisetum limosum L. f. verticillatum (Doell.) Nakai
Equisetum fluviatile L. var. limosum (L.) Gilbert (also discarded the other varieties)


Equisetum fluviatile in Hokkaido and Alaska

[1/2] Hokkaido. [1] in Abira wetland, central Hokkaido, on July 16 2012. [2] in Onneto Lake, eastern Hokkaido, on June 25 2013. [3] near Akanuma (Red Pond), Kushiro Moor, eastern Hokkaido, on June 28 2015. [4] Alaska. at a artificial pond that was established for gold mining, near Poker Flat Research Range, on August 18 2013. [5] in Sandaohu peatland, Jilin Province, northeastern China, on June 11 2017. [6] at a ditch on the bottom of Tomamu skislope, Shimukappu Village, central Hokkaido, on July 20 2012.