Tobacco
Tobacco grows wild in Plains and Forest biomes, with roughly a 4% chance per chunk to spawn a patch (it will never spawn in a Cold or Hills-type biome). Each patch is a cluster of already fully-grown plants scattered around a point, and will only take root on grass.
Crop generation can be toggled off via the Config, so if you can't find any, it may be disabled.
If you don't want to search for it, Tobacco Seeds can also be bought from a Herbalist Villager for 2-8 emeralds.
Once planted, Tobacco grows the same as other crops, requiring sun, light and irrigated farmland.
Unlike other crops though, Tobacco keeps growing once it hits full maturity, it will start a new segment above it, up to three high.
Only fully-grown segments drop anything worth harvesting - each one yields 3-8 Tobacco Leaves when broken. The bottom segment always drops a seed so you can replant, but upper segments only have a 50% chance to drop a seed, and only once they're fully grown.
Craft 4 Cigarettes with 2 Paper and 1 Dried Tobacco.
Craft a Cigar with 6 Dried Tobacco and 3 Paper.
Craft a Blunt with 3 Dried Tobacco, 3 Dried Cannabis Buds and 3 Paper.
Craft Harmonium with 1 Dye, 1 Glowstone Dust and 1 Dried Tobacco. Any of the 16 dye colours can be used, each giving a different coloured Harmonium. Harmonium's recipe can be disabled in the Config.
9 Tobacco Leaves give 3 Dried Tobacco.
