Flux plants
This mod adds two plants that might help you with steel production on maps with little or no flux.
Flux fungi
White fungi that can be grown or harvested underground. Seeds and plants probably available at embark.
Flux bulbs
White bulbous plants that can be grown or harvested above ground, temperate biomes.
Both plants can be turned into flux at a farmers workshop (new reaction: "process flux plant to flux").
This reaction turns one plant into 2 flux stones (limestone for fungi, calcite for bulbs), and returns seeds.
Both plants can also be brewed into (sparkling) alcohol, but not cooked or eaten raw.
The "process flux plants" farmers workshop reaction is added to the "mountains" entity, so non-dwarven civs may not be able to use it.
This mod must be anywhere below the vanilla_entities in the mod order list to add the reactions properly.
As the last DF patch added support for sprout graphics, I updated the mod to include sprouts for the two plants.