Peonies are easier to buy and grow when you know how their botanical names are built. The peony scientific name is Paeonia, but that answer only tells part of the story, because the genus sits above species, hybrids, and cultivar names. Once you can read those layers, the labels in a U.S. nursery stop feeling vague and start telling you something useful.
The name is simple, but the classification does most of the work
- Paeonia is the genus for all peonies, and Paeoniaceae is the peony family.
- Species names such as P. lactiflora and P. officinalis tell you which plant you are really looking at.
- Most garden peonies sold in the United States are herbaceous types, tree peonies, or intersectional Itoh hybrids.
- Cultivar names in quotes, like 'Sarah Bernhardt', identify the exact garden selection.
- Italicized Latin names and the multiplication sign × are the quickest clues that a plant is a species, a hybrid, or a cultivar.
What the scientific name actually tells you
In botany, a name is not decoration. It is a shortcut to relationship, habit, and often garden performance. Paeonia is not a single plant but a genus, and that is why a peony can be herbaceous, woody, native, hybrid, or a named cultivar while still staying within the same family.
Peonies belong to the family Paeoniaceae in the order Saxifragales. I care about that detail because it separates peonies from other common ornamentals people sometimes lump together with them. They are not roses, not ranunculus, and not anything else in a florist’s shorthand. They are their own small botanical group, and that makes the genus name worth knowing.
Different checklists can disagree on the exact species count, which is normal in a genus with a long history of selection and hybridization. I care less about chasing a single number than about knowing how the name is structured and what it tells me about the plant in front of me. From there, the hierarchy becomes easy to read.
How botanists break the name down
The part most gardeners need is not a lecture on taxonomy. It is a quick way to read the label. Here is the structure I use when I want the name to tell me something practical.
| Rank | Example | What it tells you |
|---|---|---|
| Order | Saxifragales | The broader evolutionary group peonies belong to. |
| Family | Paeoniaceae | Peonies sit in their own small family. |
| Genus | Paeonia | The core peony name people usually mean. |
| Species | P. lactiflora, P. officinalis | The natural species within the genus. |
| Hybrid | Paeonia × something | Crossed material, common in modern breeding. |
| Cultivar | 'Sarah Bernhardt' | The exact selected garden form you buy. |
The multiplication sign × matters because many garden peonies are hybrids rather than pure species plants. That is one reason two labels can both say peony and still produce very different shrubs, flowers, and winter behavior. Once that is clear, the main garden groups make much more sense.
The main peony groups gardeners see
In U.S. gardening, peonies usually fall into three practical groups: herbaceous peonies, tree peonies, and intersectional Itoh hybrids. I like this split because it reflects how the plant behaves, which is ultimately what the gardener needs to know. Flower form matters too, but habit comes first.
| Group | What it is | What it means in practice |
|---|---|---|
| Herbaceous peonies | Soft-stemmed perennials that die back to the ground in fall | The classic border peony; easy to recognize, easy to place, and often hardy in USDA zones 3 to 8. |
| Tree peonies | Woody deciduous shrubs, not true trees | They keep their above-ground framework through winter and usually need more room; many are suited to zones 4 to 8. |
| Itoh peonies | Intersectional hybrids between herbaceous and tree peonies | They blend strong stems with large, showy blooms and are popular when gardeners want a sturdier ornamental plant. |
| Species peonies | Wild, naturally occurring species | Useful for collectors, breeders, and gardeners who want a plant with a clearer botanical identity. |
For a home garden, the most important distinction is winter behavior. Herbaceous peonies retreat underground, tree peonies keep a woody framework, and Itoh hybrids sit between the two. That single difference affects staking, pruning, and the way the bed looks after frost, which is why the name is more than a label. It is the first clue about how the plant will live in your space.
Which species names matter most in the United States
For American gardeners, a few Latin names appear again and again. Paeonia lactiflora is the backbone of many classic herbaceous garden peonies and florist-style blooms. P. officinalis shows up in older European selections, while tree peonies are often labeled with P. suffruticosa or related hybrids in the trade.
Native species such as P. brownii and P. californica matter more to wild plant enthusiasts and restoration-minded gardeners than to a typical border bed. I think that distinction matters. A garden peony bred for showy flowers and long stems is not a good stand-in for a native species, and a wild species is not always the easiest choice for a beginner. The Latin name tells you which lane the plant belongs in.
That is also why common names can be misleading. “Peony” is helpful at the casual level, but it does not tell you whether the plant stays woody, dies back in winter, or behaves like a cut-flower selection. The species or hybrid name is what gives the plant a real identity.
How to read a nursery label without guessing
A complete label gives you more than a flower picture ever will. Paeonia lactiflora 'Sarah Bernhardt' tells me I am looking at a lactiflora-derived herbaceous peony and a specific double-pink cultivar, while Paeonia 'Bartzella' tells me I am probably dealing with an intersectional hybrid rather than a straight species plant. The details are small, but the difference in the garden can be large.- Italicized Latin words usually mark the genus and species.
- Single quotes mark the cultivar name.
- × points to a hybrid cross.
- Herbaceous perennial means the stems die back each winter.
- Deciduous shrub usually means a tree peony habit.
The biggest mistake I see is assuming the common name is enough. It rarely is, because the same word “peony” can hide very different growth habits, bloom windows, and support needs. Flower form is another layer entirely: single, Japanese, semidouble, double, and bomb are ornamental descriptions, not taxonomic ones. If you want to compare plants honestly, the botanical name comes first and the flower description comes second.
Why this Latin name makes buying and planting easier
In U.S. conditions, that label matters when you place the plant. Herbaceous peonies are often hardy in zones 3 to 8, tree peonies commonly in zones 4 to 8, and bloom windows usually fall between April and June, with individual cultivars often flowering for only 7 to 10 days. That short bloom period is one reason I recommend mixing types instead of betting everything on one plant.
- Choose herbaceous peonies when you want classic border plants with reliable dieback and simple winter cleanup.
- Choose tree peonies when you have room for a woody shrub and want a more permanent framework in the garden.
- Choose Itoh hybrids when you want stronger stems and a broader color range without fully committing to a tree form.
- Use the full botanical name when you want to compare cultivars honestly, not just rely on a generic common name.
For me, the real value of the botanical name is predictability. It helps you match bloom time, mature size, winter dieback, and hardiness to the spot you actually have. Once you know how Paeonia is organized, you can choose a peony that fits your climate, your soil, and the amount of patience you actually have.
