火焰花种子 can be obtained by harvesting 火焰花 while it is blooming. In desktop versions of Terraria, a Fireblossom will bloom when the sun is setting if it is not raining, from 3:45pm to 7:30pm. In console and mobile versions, Fireblossom plants must be at least partially submerged in 熔岩 before they will bloom and yield seeds. At this time each plant will drop 1-3 Fireblossom Seeds.
Fireblossom Seeds can be placed in empty 粘土盆s or on 灰烬块s and grown into additional, harvestable Fireblossom. Potted Fireblossom will grow anywhere, not just in the 地狱, but will only yield seeds when blooming.
Like the Fireblossom, this item is immune to lava despite not being of blue quality.