Stems

1. **Herbaceous Stem**: These stems are soft, green, and flexible. They are usually found in plants like grass and herbs. Herbaceous stems are capable of performing photosynthesis.

2. **Woody Stem**: Woody stems are hard and rigid. They provide support to the plant and help in transporting water, nutrients, and sugars. Trees and shrubs typically have woody stems.

3. **Underground Stem**: Underground stems grow below the soil surface. Examples include rhizomes, tubers, and bulbs. They store food, help in vegetative propagation, and provide support to the plant.

4. **Aerial Stem**: Aerial stems grow above the ground. They support the leaves, flowers, and fruits of the plant. Examples include runners, stolons, and tendrils.

5. **Specialized Stem**: These stems have unique functions adapted to specific plant needs. Examples include thorns, cladodes, and phylloclades. They serve purposes like protection, water storage, or photosynthesis.