Cactus Flowers are cubic blocks of green cacti with yellow flowers on them, each of these consisting of four yolk yellow denticulated petals with orange center and tips that protrude from the blocks a little.
These solid flower blocks can be found on "naturally grown" Cacti in Dunes and Canyons in any newly created Creativerse game world as part of the prefabricated template worlds, and some more of them can grow in time on natural Cactus blocks under certain circumstances.
Cactus flowers can also rarely be dropped by or pet-harvested from Dried Leafies. They cannot be multiplied by placing them and picking them up repeatedly though.
Cactus Flowers can be placed into the world as cubic blocks just like they are, but are able to rarely make aggressive and non-aggressive Creatures spawn. Different from Wildwood Flowers, Cactus Flowers don't glow in the dark in any way.
These flowers can very easily be grown on green blocks of Cacti that you can place yourself pretty much everywhere (except into liquid lava) and into any environment even in complete darkness, as long as you will place ca. 9 Cactus blocks or more together and will leave enough free space above. You should also take care to not let them catch fire, since these Flowers are flammable.
How to obtain
You can harvest Cactus Flowers from natural Cacti of different size that can be found in Canyons and Dunes (Sandy Deserts) or when these flower blocks have "grown" on cactus blocks that have been placed by players. To collect them, no Power Cell is required and no Mining Cell will lose durability when harvesting Cactus Flowers, except for outdated Wood Mining Cells.
Cactus Flowers will also rarely be "dropped" by Dried Leafies and perhaps very rarely by Trogs and Dustevils either as a loot if you kill them (since all three Canyon Creatures also drop blocks of green Cacti.
How to use
Cactus Flowers can also be used as an ingredient in Basic Health Potions, Stone Mining Cells, Taming Collars, Golden Potions, Speed Potions, Heart-Shaped Boxes, Candy Skull Statues, Grumm's Temple Garden and in other such crafting recipes that will accept any type of Flowers.
These flowers - like plain flower-less Cactus-blocks alike - can be placed as building-blocks too, since they have a cubic shape. They can be fully rotated into all directions by pointing your cursor at them, then pressing and holding R (as the default key) and then moving the mouse while holding down the left mouse button. The chosen rotation angle can be "locked" too by simply typing "r" while looking at an already rotated block or item, so that all blocks of the same stack in the chosen quickslot will then face the same direction when being placed.
However these natural flower blocks are able to make aggressive Dustevils or ordinary green Leafies spawn during the day. They have once been known to rarely make Dried Leafies spawn during daytime too, but this might only be possible if enough Cactus blocks are around.
Cactus Flowers can be put on display in display containers like Placemats, Stone Wall Shelves, Hidden Temple Altars, Galactic Grav-Chambers, Frozen Containers, Holiday Decorative Trees, Snow Buried Containers, Wood Planters, Flower Pots or the like, where they will be displayed in a smaller size and won't be able to spawn any Creatures.
When green Cactus blocks are put into slots of display containers, including Wood Planters and Flower Pots, no Cactus Flowers will grow on them. Also, anything that is placed into slots of display containers cannot be rotated.
More details about how to grow Cactus Flowers
You can grow Cactus Flowers easily by placing Cactus blocks close together (best into one chunk 16x16x16). You have to place a certain number of Cactus blocks into an area until Cactus flowers will start to spawn randomly here or there. 9 blocks will be enough to grow 2 flowers.
These flowers cannot be multiplied by simply placing them and picking them up again.
Cactus flowers will not grow on each single cactus block or cactus-pillar.
Instead a minimum number of Cactus blocks has to be placed into an area for Cactus Flowers to start growing, and there is also a limit for how many Cactus Flowers can grow within an area at max.
So you can only grow a small number of Cactus Flowers at once, no matter how many more Cactus blocks you will add to this area. This also means that you will have to harvest some of the flowers that have grown before any new flowers will be able to spawn.
Examples: when placing 9 Cactus blocks together, only a maximum of 2 Cactus Flowers will grow. However if you place 12 Cactus blocks together, still not more than 2 Cactus Flowers will spawn. When placing 18 Cactus blocks, 3 Cactus Flowers can spawn, but not more.
You don't need to leave spaces between your "artificial" cacti, as Cactus Flowers will only grow on top (not on the sides) of Cactus blocks. But creating walls or large cubes made of cactus blocks sticking together would be a waste, since flowers extremely rarely seem to spawn directly next to each other. Occasionally 2 flowers might spawn on top of each other though, and diagonally spawning flowers are also not rare.
You can put blocks of cacti onto any kind of blocks (yes, also crafted ones) to grow flowers - except for liquid Lava of course, as this would set Cactus-blocks on fire and consume them. Of course you will have to leave (1-2 blocks of) free space right above the Cactus blocks so Cactus flowers can spawn directly on them. Like all other regrowing flowers, Cactus Flowers will not spawn at the sides but only on top of Cactus blocks.
On pillars looking like "naturally" grown Cacti, Cactus Flowers will usually spawn very quickly, within a few minutes. If you build 1-block-flat platforms or just 2 blocks, it will take significantly longer for Cactus Flowers to grow than when building pillars of 3 blocks in height or more.
Cactus Flowers do not need any light to grow (Creativerse is not like Minecraft in this aspect), so like Crops, these flowers will even grow very well underground, with or without torches placed nearby.
These flowers are sturdy enough to also grow well in snowy areas like Frozen Deserts, on high altitudes, in Swamplands and even on the Corruption layer - as long as there is enough free space upwards so that Cactus Flowers can spawn on top of Cactus blocks. This same principle does not apply to all kinds of flowers in Creativerse!
Cactus Flowers are the fastest kind of flowers that you can grow yourself. You don't need to stay close to blocks of Cacti to make Cactus flowers grow, and staying close will also not speed up their growth. Cactus Flowers can grow during (ingame-)night times too and while you're offline, but their growth time is still random, they won't take any specific amount of time like Seeds need to grow into Crops or Saplings need to grow into trees.
Attention: like nearly all plants and flowers in Creativerse, including whole trees, blocks of Cactus Flowers and also green Cactus blocks are flammable! When placing Cactus Flowers and/or Cacti close to (or especially directly above) torches or any other items with open flames or fiery blocks like Hardened Lava, Cactus Flowers and Cacti can easily catch fire and burn to nothingness in hot environments that make a heat meter show up, like Oceans, Jungles or the Lava layer, but also in much cooler Swamplands.
Placing several torches or heat sources with open flames next to each other can even raise the chances to set flammable objects like Cactus Flowers and Cacti on fire. Liquid Lava or Fire Bombs will immediately set Cactus Flower blocks on fire.
If Cactus Flowers or green Cactus blocks start burning, the flames are then able to spread to other nearby flammable blocks, even across gaps of 1-2 blocks on game worlds and player claims where the "fire spreading" option is enabled. This way a whole wooden building or forest (especially Wildwood, Parchwood and Shorewood) can burn down in the worst case.
Fire cannot be extinguished by using liquids, but it can be stopped from spreading by claiming the area and making sure that the claim (advanced) option "fire sim/spreading enabled" is disabled (by default). Fire Bombs will have no effect on these claims either.
It is also possible for owners of the game world (F2P players included) to toggle the spreading of fire on a whole game world in the basic world options ("edit world" and "disable fire spread"). Another option to stop fire from spreading would be to create forest aisles/swaths wide enough so that the flames cannot leap over.
Also Hardened Lava, Igneous Rock and Sulfur can burn Cactus blocks as well as Cactus Flowers if you place them into any hot surrounding, since overall the environmental temperature will decide if flammable blocks will start to burn or not.
So if you try to grow Cacti on the Lava layer (which is not really recommended anyways), you should take care to leave at least 3 blocks of free space upwards, otherwise Cactus Flowers that grow on top might touch hot rocks above and will then set the whole Cactus on fire, plus perhaps also other flammable blocks nearby as well.
Cacti and Cactus Flowers are not part of very old game worlds created during Early Access before April 8th 2015, since they were implemented with update R14.