pelargonium zonale laeti
Tattoo Geraniums are not themselves magical; they are flowering plants that have been deliberately bred for ritual magic susceptibility. More specifically, the Geraniums can be used to ‘draw’ permanent magic sigils and designs outdoors, using the living plants as the ‘ink.’ The sigils drawn this way tend to be fairly robust, as a by-product of the enchantment process: it is difficult to deliberately destroy any individual Tattoo Geranium. But if one of the plants is destroyed, it can be swapped out with another one of the same color.
Contrary to popular belief, sigils ‘drawn’ this way do not disappear in the winter, but the colors of individual Geraniums often do need to be taken into account during the original enchantment. It also must be admitted that there is usually a deliberate attempt at an aesthetic. In the end, though, the important thing is that the pattern is maintained; even a ‘wrong’ colored Geranium will help the enchantment maintain coherence.
Still, the things of real interest about Tattoo Geraniums — at least, of real interest to adventurers — are the seeds and cuttings of the various varieties. The subtler the color, the more valuable the Tattoo Geranium is to archmages and enchanters, and even the most common colors (the basic spectrum, plus black and white) are pretty expensive. In other words: they’re well worth trading, looting, stealing, reiving, and even just growing, for people with magical ability and a way to guard their seed garden.
The resulting potential plot hooks should hopefully be obvious.