1. In botany, a stalk or stalklike structure; such as, the stem support of the cap of a mushroom or the stalk of a seaweed frond.
2. The stem-bearing pileus (top cap-shaped part of a mushroom or other fungus) in agarics (fungi having umbrella-like caps), boletes (umbrella-shaped cap with spore-bearing tubules on the underside and including both edible and poisonous species), etc.
3. The stalk of seaweeds.
4. The stem or caudex (axis or stem of a woody plant) of palms and tree-ferns.
5. A stem of fern fronds or leaves.