(First upload on February 17 2015. Last on January 7 2016) [ 日本語 | English ]

Potamogeton natans L.

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

Potamogeton L. (ヒルムシロ)

Ohirumushiro (オヒルムシロ, 御蛭蓆), floating pondweed
Lifeform: aquatic perennial forb
Distribution: cosmpolitan in the temperate and cool regions of the Northern Hemisphere, including Japan (rare in the southern part)

Habitat: ponds and slow-streamed reviers ⇒ wetland (湿原)
Leaf: developing floating and submergedd leaves

Submerged leaf: linear, most leaves lost when flowering ↔ P. distinctus: petiole lanceolate


Potamogeton natans in Hokkaido

[1] at a riverside veiwing from a canoe in the Bekanbeushi River, eastern Hokkaido, on July 3 2014. Akkeshi Waterfowl Observation Center is not so far from the observation site. [2/3] at an artificial pond in the park of Nakatonbetsu Limestone Caves for Communication with Nature (中頓別鍾乳洞自然ふれあい公園), northern Hokkaido, on August 28 2015. Records: in Shiretoko Five Lakes Aera, eastern Hokkaido, on August 29 2020.