(First upload on May 1 2008. Last on January 5 2018) [ 日本語 | English ]

Equisetum arvense L.

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

⇒ Engler's syllabus (エングラー体系)

Equisetaceae Michx. ex DC (トクサ, horsetail)

The family consists of one genus (etymology)
E. arvense L. (スギナ)
E. fluviatile L. (Syn. E. limosum L.) (ミズドクサ)
E. hyemale L. (トクサ)
E. palustre L. (イヌスギナ)
E. pratense Ehrh. (ヤチスギナ)
E. ramosissimum Desf. (イヌドクサ)

var. ripense (Nakai et F. Maekawa) Tagawa (タカトクサ)

E. scirpoides Michx. (ヒメドクサ)
E. sylvaticum L. (フサスギナ)
E. variegatum Schleich. ex Weber et Mohr (チシマヒメドクサ)
Putative hybrids
E. × moorei Newn. = E. ramosissimum × hyemale (トリトクサ)
E. × rothmaleri C. N. Page = E. palustre × arvense (フォーリースギナ)
E. × litorale Kuhlew. ex Rupr. = E. fluviatile × arvense (ハマスギナ)

Equisetum arvense in the Northern Hemisphere

Equisetum L. (トクサ)

Sugina (スギナ, 杉菜) or Tsukushi (ツクシ, 土筆), common horsetail (field horsetail)
Lifeform: a bushy, perennial, and rhizomatous horsetail
Morophology: highly variable (often misidentified)
Distribution: native to the Northern Hemisphere (cosmopolitan)
Habitats: common on roadside, waste ground, and grassland

HUSTEP: Plants and Plant communities in Japan (flora list)
→ Nature on lakes, volcanoes, sea and forests (海と湖と火山と森林の自然)

f. boreale (Bong.) Milde (オクエゾスギナ), triangular branches
f. campestre (Schultz) Klinge (ミモチスギナ), developing sporphylls on the vegetative shoots, non-specific forma

[1] fertile stems, taken in front of GSEES, Hokkaido University, Sapporo, on April 22, 2008. [2] at the mouth of Haboro River, northern Hokkaido, on April 24 2016. [3] vegetative stems in back of Faculty of Agriculture, HU, on April 29, 2009.
[4] on a grassland dominated by E. arvense on May 20 2017. [5/6] at the side of a building (guest house) in Tomakomai Experimental Forest on September 14 2017.

f. campestre

[1/2] at a roadside, N28/E2, Sapporo, on August 3 2015.

Morphology sketched on May 10 1983. The sample was taken in the HU campus.
Near Toolik Lake LTER Station, interior Alaska, on August 8 2009. You also see
Equisetum variegatum in the back.