It should not be a surprise that composites are such an important part of the park's flora, as they are reputed to be one of the largest families of plants with about 1,100 genera and 20,000 species. This family is unusual in that it reaches its greatest diversity in open, temperate areas such as prairie and steppe habitats rather than in tropical forests where many other plant families are most diverse.
Source: tatoeba (12294342)