How the flowers in this guide are classified, and why it is worth knowing
Every flower belongs to a chain of groups running from the very broad to the very particular, and that chain is what taxonomy is. On a site about buying and handling flowers it is not decoration. The group a plant belongs to predicts how it behaves: two flowers in the same family usually drink at the same rate, fail in the same way and answer to the same treatment, which is why somebody who knows the families is rarely caught out by a variety they have never handled before.
Four ranks are used here. Botany recognizes more, and most of them mean nothing to anyone standing in front of a bucket of flowers. These four are the ones that change what you do.
The arrangement below follows the modern classification, which is built on DNA rather than on appearance. That matters more than it sounds, because appearance had things in the wrong place for two centuries. Poinsettia sits with the willows. The sacred lotus is a closer relative of the protea than of the water lily it looks exactly like. Rather more of what you eat turns out to be related to what you put in a vase than anybody expects.
One plant, the rose, shown at each rank in turn
Rosales
The broadest rank on this site. An order gathers whole families that share a deep common ancestry, old enough that the members can look nothing like one another.
In this guide: 24 orders
The 24 orders
Rosaceae
Plants built to the same plan. This is the rank that matters most once a flower is cut, because a family tends to drink at the same rate, fail the same way and answer to the same treatment.
In this guide: 48 families, each with a page
All 48 families
Rosa
The first word of the scientific name, and the point where plants start looking like obvious relatives. A genus holds species close enough that a grower treats them as one crop.
In this guide: 102 genera, 5 of them holding more than one flower
The 5 genus pages
Rosa gallica
The individual plant, named by its genus and then one word of its own. There is no separate species section here because the species is the flower page itself.
In this guide: 108 flowers, each its own page
Learn about flowersEvery flower in this guide, filed the way a botanist would file it: 108 flowers in 48 families in 24 orders. The order and the family are links to their own pages, and where a genus has a page the first word of the scientific name is a link too.