What is a "sola topi"?

A sola topi is a type of hat that is worn primarily in India and is associated with the Indian Army. It is made from sola, a plant-based material that is derived from the pith of the Aeschynomene aspera plant, and is therefore lightweight and breathable. The hat has a distinctive shape, with a flat crown and a wide brim that is often turned up at the sides. It is typically worn with the brim turned down to provide protection from the sun, and is often decorated with a chinstrap or a ribbon. The sola topi is commonly worn as part of the uniform of the Indian Army but is also used as a traditional headwear for civilians, particularly in rural areas.