Green leaf microphyllous plants belong to the group Lycopsida.

Explanation:
- Lycopsida is a group of plants commonly known as club mosses or ground pines.
- These plants are characterized by having small, scale-like leaves called microphylls.
- Microphylls are typically arranged in a spiral pattern around the stem and are usually less than 1 cm in size.
- Unlike the leaves of other plant groups, such as ferns and flowering plants, microphylls have only a single vein, rather than a network of veins.
- The small size and simple structure of microphylls are believed to be primitive traits that evolved early in the history of vascular plants.
- Lycopsids are typically herbaceous plants, although some species can grow into small trees.
- They reproduce by spores and have a unique reproductive structure called a strobilus, which contains sporangia that produce the spores.
- Lycopsids are a very ancient group of plants that were abundant during the Carboniferous period, about 300 million years ago.
- Today, they are relatively rare and can be found in moist, shady habitats such as forests and wetlands.
- Some common examples of lycopsids include the club mosses (Lycopodium) and the quillworts (Isoetes).

In conclusion, green leaf microphyllous plants belong to the group Lycopsida, which is characterized by its small, scale-like leaves called microphylls.