The carnation and pink genus
Dianthus gave the English language a color word, and it did so backward from the way almost everybody assumes. It also produced, from an unremarkable Mediterranean wildflower, what was for a long stretch of the twentieth century the most grown cut flower on earth.
around 340 species
Europe and Asia, with a strong center around the Mediterranean
Everything in this guide that belongs to Dianthus
Ask which came first, the color pink or the flower called a pink, and nearly everyone answers the wrong way round. The flower is older. Small fringed dianthus were being called pinks in English well before the word meant a color at all, and the color took its name from them in the seventeenth century.
What the flower was named for is the edge of its petals. To pink something is to cut it with a notched or serrated edge, which is the same verb that gives pinking shears their name, and the petals of these flowers look exactly as though somebody has run a pair down each one. The plant was named for how it was cut, and a color was named after the plant.
The scientific name went the other way and aimed high. Dianthus is from the Greek for the flower of Zeus, given by Theophrastus more than two thousand years ago, which makes it one of the oldest plant names still in use for the plant it was coined for.
The old cottage pinks and the original carnation species share a scent that is unmistakable and that has nothing floral about it: warm, spicy and recognizably clove. That is not a poetic comparison. The plants make the same aromatic compound cloves do, which is why the description keeps arriving independently in every language that has a word for both.
It mattered historically. Before the spice trade made cloves affordable in northern Europe, flowers from this genus were used to spice wine and ale as a cheap local substitute for the imported article, and several of their old names refer to that rather than to anything ornamental.
Modern breeding has largely spent it. Selecting hard for stem length, color range, bloom size and vase life pulled the scent out of most commercial lines, and it is now a thing to check for rather than to assume. The plants that kept it are mostly the older garden types and a handful of varieties grown deliberately for it.
Wild carnations flower once a year, in early summer, and stop. That is useless commercially, and the entire modern industry rests on breaking it.
French breeders in the middle of the nineteenth century produced the first reliably perpetual flowering carnations, plants that would keep producing buds continuously rather than in one flush. American growers took those, pushed them further and built the twentieth century glasshouse carnation trade on them, to the point where for decades it was among the most grown cut flowers anywhere and was often the single biggest.
It has since been overtaken and it has also been quietly rehabilitated. The carnation spent a long period as the flower nobody admitted to liking, largely because the cheap dyed ones were everywhere, and the specialist and scented types have brought it back into serious floristry over the last decade or so.
Every flower in this genus sits in a narrow rigid tube formed by its fused sepals, and it is a tighter piece of engineering than it looks. The petals are packed inside that tube with their bases clamped, which is what holds the head together and why a dianthus flower does not shed petals one at a time the way a rose does.
Push it too far and it fails in a specific way. If a bud develops faster or fuller than the tube can accommodate, usually after a warm spell or in a heavily doubled variety, the tube splits down one side and the flower spills out lopsided. It cannot recover, and growers of large headed carnations routinely slip a small band around the calyx before it opens to stop it happening at all.
The same construction is why the stems have such obvious swollen joints. Those nodes are where the leaves attach in opposite pairs, they are the strongest points on an otherwise thin stem, and they are also where it snaps when it snaps.