Nature Diary
Bombax Ceiba, the Silk cotton tree

Indian Names: Simul, Roktosimul, Malabar Semul, Elava Maram, Buruga, Kapok tree

Silk cotton tree is a type of native cotton tree with large red flowers. The genus name Salmalia is derived from the sanskrit name shaalmali.
The trees bear beautiful red-colored flowers during January to March. It paints the whole landscape in an enchanting red colour. The fruit, the size of a ping-pong ball, on maturity appears during March and April. These are full of cotton-like fibrous stuff. It is for the fibre that villagers gather the semul fruit and extract the cotton substance called "kopak". This substance is used for filling economically priced pillows, quilts, sofas etc.
The fruit is cooked and eaten and also pickled. Semul is quite a fast growing tree and can attain a girth of 2 to 3 m, and height about 30 m, in nearly 50 years or so.
Its wood, when sawn fresh, is white in color. However, with exposure and passage of time it grows darkish gray. It is very light with a density of about 0.4 gm/cc. It is easy to work but not durable anywhere other than under water. So it is popular for construction work, but is very good and prized for manufacture of plywood, match boxes and sticks, patterns, moulds, etc. It is also used for making canoes and light duty boats and or other structures required under water. The wood is soft and is often used for making paper, while in rural areas, it is used as fuelwood and for making cheap furniture.
Bombax species are used as food plants by the larvae of some species including the leaf-miner moth species Bucculatrix crateracma which feeds exclusively on Bombax ceiba.
The golden-crowned sparrow weaves the lining of its nests with white cotton from its seeds.
Sources: Wikipedia, https://www.flowersofindia.net/catalog/slides/Silk%20Cotton%20Tree.html