Sweet Flag (Acorus calamus) is a perennial herbaceous plant known for its aromatic foliage. It's often grown for its ornamental value, especially in water gardens and moist or boggy areas. Here are some key features and care tips for Sweet Flag (Carex is a related genus, but Sweet Flag is often associated with Acorus calamus):

1. Foliage: Sweet Flag has long, sword-shaped leaves that emit a sweet fragrance when crushed. The foliage is a beautifully variegated, green and yellow.

2. Size: The size of Sweet Flag typically reaches a height of 10-12 inches, with a spread of 6-8 inches.

3. Sunlight Requirements: Sweet Flag can tolerate a range of sunlight conditions, from full sun to partial shade. However, it often performs best in partial shade to full shade.

4. Soil and Moisture: Sweet Flag thrives in consistently moist to wet soil, making it suitable for planting in water gardens, along pond edges, or in boggy areas. It can tolerate standing water for short periods.

5. Hardiness: Sweet Flag is hardy in USDA zones 5 to 11. It is well-suited for a variety of climates.

6. Container Planting: Sweet Flag can be grown in containers filled with a mix of soil and aquatic compost. This is especially useful if you want to enjoy its ornamental qualities on patios or balconies.

7. Maintenance: Sweet Flag is generally low-maintenance. Remove any dead or yellowing leaves to maintain a tidy appearance. If the plant becomes too large or crowded, it can be divided in the spring.

8. Propagation: Sweet Flag can be propagated through division. Divide mature clumps in the spring to create new plants.

9. Winter Care: In colder climates, the foliage of Sweet Flag may die back in winter. Cut back the dead foliage in late winter or early spring to make way for new growth.

10. Landscaping Use: Sweet Flag is commonly used in water gardens, ponds, and along water features. Its upright, arching foliage provides a striking contrast and texture in garden landscapes.

11. Aromatic Qualities: The aromatic foliage of Sweet Flag is sometimes used for its pleasant scent. It's important to note that there are different chemotypes of Sweet Flag, and some may contain compounds that are not recommended for internal use.

It's a versatile plant that can add both visual and aromatic interest to your garden, especially in moist or aquatic settings.