Explanation:

- Spirogyra is a type of green algae commonly found in freshwater habitats.

- It belongs to the group known as Thallophyta.

- Thallophyta includes simple plant-like organisms, primarily algae and fungi.

- Bryophyta: This group includes non-vascular plants like mosses and liverworts.

- Angiosperms: These are flowering plants with seeds enclosed within a fruit.

- Pteridophyta: This group comprises vascular, non-flowering plants like ferns.