Chrysanthemum

Chrysanthemums, often called mums or chrysanths, are perennial herbaceous flowering plants from the Asteraceae family that flower in autumn. They are native to East Asia and northeastern Europe, with most species coming from East Asia and the greatest variety found in China. Countless horticultural varieties and cultivars exist.

Description

The plants are perennial herbs, sometimes subshrubs. Their leaves grow alternately, are divided into leaflets, and can be pinnatisect, lobed, or serrated, though rarely entire; the leaf stalks have hairy bases. The flower heads form a compound inflorescence, either in clusters or alone. Each head sits on a base covered in layered phyllaries.

A single row of ray florets may be white, yellow, or red, while the disc florets are yellow. Pollen grains measure about 34 microns. The fruit is a ribbed achene.

Etymology

The name comes from the Ancient Greek chrysos (gold) and anthemon (flower).

Taxonomy

Linnaeus first formally described the genus in 1753, listing 14 species, so his name (L.) is the botanical authority. The genus once included more species but was split decades ago into several genera, moving the commercially important florist's chrysanthemums into Dendranthema. Naming became contentious, but a 1999 International Botanical Congress ruling changed the defining species to Chrysanthemum indicum, returning florist's chrysanthemums to Chrysanthemum. Genera now separated include Argyranthemum, Glebionis, Leucanthemopsis, Leucanthemum, Rhodanthemum, and Tanacetum.

As of September 2025, Plants of the World Online accepts the listed species. Former species include Chrysanthemum carinatum (now Ismelia carinata), C. cinerariifolium (Tanacetum cinerariifolium), C. coccineum (Tanacetum coccineum), C. coronarium (Glebionis coronaria), C. frutescens (Argyranthemum frutescens), C. maximum (Leucanthemum maximum), C. pacificum (Ajania pacifica), and C. segetum (Glebionis segetum).

Cultivation

Cultivation began in China as early as the 15th century BCE, with over 500 cultivars recorded by 1630. By 2014, an estimated 20,000 cultivars existed worldwide, about 7,000 in China. The plant is one of the Four Gentlemen in East Asian art and is especially important during the Double Ninth Festival. In Japan, cultivation started in the Nara and Heian periods (early 8th to late 12th centuries) and became popular in the Edo period (early 17th to late 19th centuries).

Many flower shapes, colors, and varieties emerged, and growing techniques developed. Edo-period cultivars were exported to China, influencing Chinese cultivation. From the Meiji period (late 19th to early 20th centuries), the Ogiku style—flowers over 20 cm in diameter—was created.

The imperial crest of Japan is a chrysanthemum, and the monarchy is called the Chrysanthemum Throne. Autumn festivals and shows occur across Japan. Chrysanthemum Day, one of the five ancient sacred festivals, is celebrated on the 9th day of the 9th month, starting in 910 with the first imperial chrysanthemum show. In the U.S., Colonel John Stevens imported the Dark Purple variety from England in 1798 for Elysian Fields in Hoboken, New Jersey.

For horticulture, all cultivars are divided into 13 categories based on flower form, as classified by the National Chrysanthemum Society (USA).

Modern cultivated chrysanthemums are often brighter and more striking than wild types. Many have been bred to have multiple rows of ray florets in various colors. Flower heads range from daisy-like to pompon or button forms.

The genus includes many hybrids and thousands of horticultural cultivars. Besides traditional yellow, colors include white, purple, and red. The key hybrid is Chrysanthemum × morifolium (syn. C. × grandiflorum), mainly from C. indicum but involving other species.

Over 140 cultivars have received the Royal Horticultural Society's Award of Garden Merit (confirmed 2017). In Japan, chrysanthemum bonsai developed over centuries; the plant lives about five years and can be kept miniature. A bonsai-like effect is also created by growing the flower over dead wood to suggest a miniature tree.

Yellow or white flowers of C. morifolium are boiled to make tea in parts of East Asia, known as chrysanthemum tea.