Nitella flexilis bifurcata Kasaki (1964)



Taxonomy & Nomenclature



Conservation Status

Last record: 1958 (Sakayama et al., 2015)

Rediscovered (Sakayama et al., 2015)


Previously only known from the type collections from Lake Chuzenji in 1958 (Sakayama et al., 2015) and then considered extinct (Watanabe et al., 2005). It was rediscovered (Sakayama et al., 2015) on 30 June 2000 or later (Sakayama et al., 2002, 2015).



Tochigi Prefecture (Lake Chuzenji; Lake Suge-numa; Lake Yuno), Honshu, Japan

Type locality:  Lake Chuzenji, Tochigi Prefecture, Honshu, Japan (Kasaki, 1964)


Biology & Ecology




Type specimens:

Lectotype (designated by Sakayama et al., 2015:163): MAK A12404

Isolectotype (designated by Sakayama et al., 2015:163): MAK A17611–MAK A17620 and MAK A22963

Syntypes (designated by Sakayama et al., 2015:163): MAK A21063 and MAK A21587

Isosyntypes (designated by Sakayama et al., 2015:164): MAK A22180, MAK A21588, MAK A21589 and MAK A22946






Original scientific description:

Kasaki, H. (1964). The Charophyta from the lakes of Japan. J. Hattori Bot. Lab. 27: 215-314.


Other references:

M.D. Guiry in Guiry, M.D. & Guiry, G.M. 02 August 2018. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.; searched on 24 September 2023.

Imahori, K. and Kasaki, H. (1977). Class Charophyceae, pp. 761-829. In: Hirose, H., Yamagishi, T. and Akiyama, M. (1977). Illustrations of the Japanese fresh-water algae. pp. [8 col. pls], [1]-933, 244 pls in text. Tokyo: Uchida Rokakuho Publishing Co., Ltd. [in Japanese]

Sakayama, Hidetoshi, Kai, A., Nishiyama, M., Watanabe, M.M., Kato, S., Ito, M., Nozaki, H. and Kawai, H. (2015). Taxonomy, morphology, and genetic variation of Nitella flexilis var. bifurcata (Charales, Characeae) from Japan. Phycological Research 63(3): 159-166. [Supporting Information: Table S1 (loaction of samples), Table S2 (primers used), Table S3 (rbcL accessions)]

Sakayama, H., Nozaki, H., Kasaki, H. and Hara, Y. (2002). Taxonomic re-examination of Nitella from Japan, based on microscopical studies of oospore wall ornamentation and rbcL gene sequences. Phycologia 41(4): 397-408. 

Sano, Satomi et al. (1997). Current state of distribution of the Charales (Chlorophyta) in Japanese Lakes, pp. 97. In: Abstracts of Papers Presented at the Sixth International Phycological Congress, Leiden, Netherlands. 130 pp.

Watanabe, M. M., Nozaki, H., Kasaki, H., Sano, S., Katon, N., Omori, Y. and Nohara, S. (2005). Threatened states of the Charales in the lakes of Japan, pp. 217-236. In: Kasai, K. and Watanabe, M. M. (eds). Algal culture collections and the environment. Tokyo: Tokai University Press. 248 pp.


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