Trichosarcina is a genus of green algae in the order Ulotrichales.

[1] As of February 2022[update], AlgaeBase accepted only one species, Trichosarcina polymorpha.

[1] Its life cycle includes a uniseriate, Hormidium-like phase; a pluriseriate stage, and, finally, a chain of sarcinoid packets which may dissociate.

The cells are uninucleate, with a parietal chloroplast and single pyrenoid.

Quadriflagellate zoospores are produced by cells of the pluriseriate and sarcinoid stages.