Wood Anemones

Wood Anemones (a slightly modified variant of real wood anemones) are small, white flowering plants which only grow on podzol and cover large areas of the ground in taiga biomes. 

First of all, they would be decorative plants, so the taiga looks a bit more colorful and less empty.

Second of all, wood anemones can be used for brewing some new potions. 

Third of all, if you hold a wood anemone in your hand, taiga villagers will offer you better items for trading. On the other hand, zombies get attracted by wood anemones, so you better be careful at night while walking around in the taiga.