What tree species, widely planted in Islamabad’s early development, is the primary source of severe seasonal pollen allergies?

💡 Explanation:

The Paper Mulberry (Broussonetia papyrifera) tree was planted extensively during the initial development of Islamabad. However, it is an invasive and highly allergenic species, and its pollen is widely recognized as the primary cause of severe seasonal allergies and respiratory problems for many residents.