Purple Bladderwort

If you have attended our latest AGMs you have often heard talk about the Purple Bladderwort (Utricularia Purpurea) in Black Lake. It is a carnivorous plant found in many places in the Eastern part of North America, but only in a very few lakes in the Laurentians. When abundant it can be bothersome but it is otherwise harmless.

This 2,5  minute underwater video was done in the far east section of Black Lake last summer. The author is none other than Dr. Richard Carignan, Quebec’s foremost lake expert. He is also an active member of the GRIL (Group for Interuniversity Research in Limnology and Aquatic Environment)

He has identified in French the plants seen in the video. I am providing you here with the appropriate English names. First, in order of appearance, is  la (Vallisnérie américaine, (Vallisneria Americana),  Brasénie de Schreber,  (Schreber Watershield), Potamot à large feuilles, (Large-Leaved Pondweed)  then lots of Purple Bladderwort. Finally,  a composite of the latter, plus vallisnérie américaine (Tapegrass) and some potamot émergé (Ribbonleaf Pondweed). All of these plants, except the Purple Bladderwort, are common in all our lakes.

We do not know how long the Bladderwort  has been living in Black lake. I arrived here in 1996 and I remember hearing about this phenomenon around that period.

Strangely, a survey of aquatic plants* on the lake produced by Vanier College in 1982 has no mention of that plant on it’s list of aquatic plants. As as this map shows, there are a lot of aquatic plants on Black Lake.


Our expert Richard Carignan, professor at University of Montreal and Quebec’s foremost lake expert, does not recommend any action at this time.

He will follow its evolution with us and advise accordingly.

* A Preliminary Aquatic Survey Boyd and Black Lakes, Quebec. Technical report No. 5a 1982  H.J. Smart  D.J. Oxley – Vanier College Fish and Wildlife Technology Program


Leave a Reply

Your email address will not be published. Required fields are marked *