The axodines are a group of unicellular heterokont algae. They typically have one emergent flagellum, extended into a peculiar wing-like form supported by an internal rod, which lacks the root structure found in most other heterokont groups. They also have tentacles or axopods supported by bundles of microtubules, which arise from the surface of the nucleus. Most forms have chloroplasts, pigmented similarly to those of other heterokonts, but some are colorless and feed by phagocytosis. There are three groups included here:
- Silicoflagellates, marine algae with produce siliceous skeletons
- Actinodines, including various algae (pedinellids) and heliozoa (ciliophryids and actinophryids)
- Rhizochromulina marina, a colored amoeboid