The peony, a member of the genus Paeonia, is an admired ornamental flower celebrated for its large, lush, and often fragrant blooms. Gardeners are drawn to its complex structure, which can range from simple elegance to extravagant fullness. The question of how many petals a peony has does not have a single answer because centuries of cultivation have produced a vast diversity of flower forms. This variability means the petal count can differ between a wild species and a highly developed garden variety.
The Variable Answer to Petal Count
The number of petals on a peony depends entirely on its classification, ranging from a handful of true petals to hundreds of floral segments. Wild peony species, the original form of the flower, typically possess a lower count of true petals, often between five and thirteen arranged in one or two simple layers. These single-form flowers clearly display the reproductive parts, such as the stamens and carpels, in the center of the bloom.
The count increases significantly in cultivated varieties, which are often classified as double-form. These flowers can have anywhere from fifty to over a hundred petals, with some massive cultivars reportedly exceeding 300 floral segments. This increase results from a genetic mutation where the stamens (male reproductive organs) are transformed into petal-like structures. The result is a dense, globular blossom where the original reproductive parts are obscured or replaced by these floral segments.
Classification Based on Petal Structure
Horticulturalists use a standardized classification system to categorize peonies based on the arrangement and transformation of floral parts, which relates directly to the final petal count.
Single Form
The Single form, resembling the wild ancestor, features one or two rows of broad outer petals (guard petals) surrounding a prominent center of stamens.
Semi-Double Form
The Semi-Double form displays multiple rows of petals intermingled with visible stamens, creating a fuller look while retaining some reproductive organs.
Double and Bomb Forms
The Double form represents the fullest expression of the peony, where almost all stamens and sometimes carpels are transformed into petals, resulting in a dense, heavy flower. The Bomb form is a specific type of double, characterized by a single row of guard petals framing a distinct, rounded mound of narrower, centrally-located petals.
Japanese Form
The Japanese form is an intermediate category where broad outer petals frame a center filled with modified, sterile stamens called staminodes, giving the center a feathery or tufted appearance.
Distinguishing True Petals from Other Flower Parts
High petal counts require distinguishing between true petals and other floral structures that resemble them. The true petals are botanically part of the corolla and include the large, outer segments known as guard petals. These guard petals provide the initial structure and color to the bloom.
The immense number of segments in double and bomb forms often includes structures called petaloids or staminodes. Staminodes are modified stamens that are flattened and colorful, resembling small, narrow petals (especially in the Japanese form). Petaloids represent a further stage of transformation, similar in color and texture to the guard petals but narrower and denser, forming the bulk of the center mass in double and bomb flowers. When counting the segments of a full flower, one is counting both the true corolla petals and these numerous, petal-like, modified reproductive structures.