Actinotaenium americanum
image © Marien van Westen

Actinotaenium americanum. Notice wide, V-shaped cell sinus. Notice also asteroid chloroplast with a single, central pyrenoid. Cell dimensions (L x B): 58 x 25 µm


Actinotaenium americanum
image © Alfred van Geest

Another cell of Actinotaenium americanum, also with storage products.


 


Desmid of the month
July 2026

Actinotaenium americanum*


Actinotaenium americanum should be compared with A. diplosporum (Desmid of November 2006) a species of which it originally was described as a separate variety. The main difference between these two taxa is in the shape of the cell sinus: a hardly marked, slight incurvation in A. diplosporum versus a wide, shallow V-shaped indentation in A. americanum. In the Netherlands, A. americanum is of occasional occurrence in various mesotrophic pools.

* Also known as Actinotaenium diplosporum var. americanum

Actinotaenium americanum
image © Alfred van Geest

Cell of Actinotaenium americanum filled with globules.