Which one of the following is not a site for in-situ methods of conservation of flora?

To determine which one of the following is not a site for in-situ methods of conservation of flora, we need to understand what in-situ conservation means. In-situ conservation refers to the conservation of species within their natural habitats. It involves protecting and managing ecosystems and habitats to ensure the survival of species.

Now, let's examine the options provided and determine which one does not fit the criteria of being a site for in-situ conservation:

1. National parks: National parks are designated areas that aim to protect and preserve natural ecosystems, including flora and fauna. They are often considered ideal sites for in-situ conservation as they provide a protected environment for species to thrive. Therefore, national parks can be considered a site for in-situ conservation.

2. Botanical gardens: Botanical gardens are designed to cultivate and display a wide variety of plant species. While they play a crucial role in ex-situ conservation (conservation outside the natural habitat), they may not necessarily be considered as sites for in-situ conservation. Therefore, botanical gardens may not be a site for in-situ methods of conservation of flora.

3. Wildlife sanctuaries: Wildlife sanctuaries are protected areas that provide a safe haven for wildlife, including plants. They aim to conserve and protect the natural habitat of various species. Therefore, wildlife sanctuaries can be considered a site for in-situ conservation.

4. Seed banks: Seed banks are facilities that store and preserve seeds of various plant species. They are primarily involved in ex-situ conservation by collecting and storing seeds for future use. While seed banks play a crucial role in preserving plant diversity, they do not directly contribute to in-situ conservation. Therefore, seed banks may not be considered a site for in-situ methods of conservation of flora.

Based on the above analysis, the option that does not fit the criteria of being a site for in-situ methods of conservation of flora is "Botanical gardens."