Britton's Chara

By Laura Briscoe

May 13 2019

In the United States, there is no formal regulation for the endangered species of algae, so none are officially listed as endangered. However, we know from herbarium records that some species are incredibly rare and are vulnerable to extinction.

Britton's Chara (Chara brittonii) is a species of freshwater algae first described in 1906 based on a single collection made in New Jersey by New York Botanical Garden's co-founder, Nathaniel Lord Britton. Before 2001, this species was known from just seven localities (in addition to the type locality) in the United States, and has been considered one of the rarest Characeae in the world.

New York Botanical Garden's algae curator Ken Karol and his colleagues have assessed the historical localities of this species, and were only able to locate Chara brittonii from three of the seven historical localities, but also found six new localities of the species, including a new record of the algae from Wisconsin.

This diminutive algae may be in fact wide-spread in the Great Lakes region, but infrequent and often overlooked. Through the study of living populations and herbarium specimens, we can better understand rare species like this, and hopefully work to protect the known localities.



Brodie, J., Andersen R.A., Kawachi, M. & Millar, A.J.K. 2009. Endangered algal species and how to protect them. Phycologia 48: 423-438.

Karol, K.G., Alix, M.S., Scribailo, R.W. et al. 2018. New records of the rare North American endemic Chara brittonii (Characeae), with comments on its distribution. Brittonia  70(3): 277-288. Retrieved from: (Accessed: 08 May 2019).

Robinson, C.B. 1906. The Characeae of North America. Bulletin of the New York Botanical Garden 4(13): 244-308.