Flowers may refer to a vanilla item or a modpack item. Some can be found in the naturally spawned world anywhere that grass exists and can be created by placing Bone Meal on grass, while others must be grown like crops. Apiaries often require flowers nearby to function, but may not recognize mod-added flowers.
List of flowers:
-Dandelion: a yellow flower added in vanilla Minecraft
-Rose: a red flower added in vanilla Minecraft
-Blackthron: a black flower added in IndustrialCraft 2
-Cyazint: a cyan flower added in IndustrialCraft 2
-Ferru: an iron flower added in IndustrialCraft 2
-Venomilia: a dark purple flower added by IndustrialCraft 2
-Tulip: a purple flower added by IndustrialCraft 2
-Aurelia: a golden flower added by IndustrialCraft 2
-Indigo Flower: a light purple flower added by RedPower 2
-Shimmerleaf: a silver flower added by Thaumcraft 3
-Cinderpearl: a fiery flower added by Thaumcraft 3
-Buttercups: an orange flower added by ExtrabiomesXL
-Purple Flower: a purple flower added by ExtrabiomesXL
-Hydrangea: a light blue flower added by ExtrabiomesXL
-Cala Lilies: a light gray flower added by ExtrabiomesXL