- Bot. a porous, woody, specialized branch growing upright into the air from the buried roots of certain swamp trees, as the mangrove, and providing access to the atmosphere
- Zool. a polyp with a gas-filled cavity in siphonophore hydrozoans, serving as a float for the colony
- A gas-filled sac serving as a float in some colonial marine hydrozoans, such as the Portuguese man-of-war.
- Botany A specialized respiratory root in certain aquatic plants, such as the bald cypress, that grows upward and protrudes above the water or mud into the air.
pneumato- +"Ž -phore