Nostoc, Euglena, and green plants all share the capability of photosynthesis, which is driven by the presence of the chlorophyll pigment (specifically chlorophyll a or similar photosynthetic pigments).

Nostoc is a cyanobacterium (blue-green algae) containing chlorophyll a.

Euglena is a photosynthetic protist containing chlorophyll a and b.

Green plants contain chlorophyll a and b.

While Euglena is mixotrophic (can be autotrophic and heterotrophic) and has flagella, Nostoc is mainly autotrophic and prokaryotic (lacks a nucleus, unlike plants and Euglena), meaning flagellation and mixotrophic nutrition are not shared by all three.