Did some plant research and made up some headcanon on how those dang bombflowers actually work.
This is all my theory and completely unofficial.
Hylian text version ::[link]
Main body of text on the sheet:
"The bomb flower is a plant native to Hyrule that is able to grow in the harshest conditions. Most commonly found in rocky or underground environments, it has adapted to surviving without the need for sunlight. While it does have leaves and undergoes photosynthesis when light is available, it does not suffer should there be a lack of light.
The bomb flower's primary source of nutrients come from the single 'deep root'. It is a thick, hard root capable of cracking stone - should it need to - as it grows and can bury itself as far down as 70 ft in it's efforts to find the water table from which it will take all the moisture it needs.
This deep root, as with all the roots, sprout from the plant's ovary chamber, which has a very hard outer shell to protect it and the unfertilized seeds it holds. The ovary chamber can hold literally thousands of unfertilized seeds. This is important for the plant, as all unfertilized seeds have the capacity to actively protect the plant from predators.
It is this method of protection from which Bomb Flowers take their name. When the bomb flower has settled itself into the ground and pushed past the surface crust with it's tiny sprout, it becomes vulnerable to the elements. As soon as the sepals open and air is allowed to touch the unfertilized seeds, a chemical reaction occurs within the ones exposed to the air. This reaction causes the seeds to start filling with an explosive natural gas, which in turn causes the unfertilized seeds to inflate. While several of the unfertilized seeds are exposed to the open air only one is able to successfully inflate and attach itself to the top of the ovary chamber, it's bottom becoming the ovary cap. This reaction occurs every time the seeds are exposed to air and is the source of the idea that the bomb flowers 'grow back' so quickly after being picked.
When the flowers are picked, if the ovary cap is not separated from the ovary chamber without a proper cover to take the place of the ovary chamber, another, slightly delayed chemical reaction occurs which causes the stamen to 'light up' like a fuse. When the fuse burns down naturally and the sparks hit the gas trapped within the inflated seed coat, the bomb flower explodes. This, combined with a certain amount of strength being needed to pick the flowers, protects the plant from would be predators.
When the bomb flower is properly fertilized, the inflated seed on top begins to grow and form the embryo and endoplasm chamber. It can take up to a month and a half for the inside of the bomb flower to replace the gas with the endosperm. At about 2-3 weeks growth, a bomb flower can be successfully harvested without risk of blowing up due to the new wall that separates the growing seed from the ovary chamber of the parent plant.
After 4-6 weeks of growth, the fully formed seed will break off from it's parent plant on it's own and roll away to continue the cycle of life. At that stage in growth, it is no longer able to explode to protect itself. Should one manage to crack one open (the outer shell, like the ovary chamber, is quite tough) a rather juicy interior can be found. The taste is otherwise bland.
If successfully harvested before fertilization occurs and without setting off the 'fuse', the bomb flower can be converted by an experienced hand into mobile bombs. Either by creating a new shell and cap to surround and protect the flower, or by extracting the gas. Should the gas be extracted, a 'bomb bag' can be created from the stretched and now flexible seed coat."