Fireblossom

Fireblossom was introduced in the 1.0.5 patch.

It appears as a small, magma-colored flower. It grows in Ash Blocks in the Underworld and can be cut with virtually any weapon or tool.

Fireblossom is an ingredient in two kinds of alchemy Potions*:

Obsidian Skin Potion - 1x Fireblossom, 1x Bottled Water, 1x Waterleaf, 1x Obsidian

Gravitation Potion - 1x Fireblossom, 1x Bottled Water, 1x Feather, 1x Blinkroot, 1x Deathweed


 * You can see this listing in-game by placing Fireblossom in the Guide's Crafting menu.

in order to get seeds from the fireblossom there must be lava touching it, then it will bloom fully and drop 1-3 Fireblossom seeds when cut.