Chrysanthemums. Chrysanthemums, sometimes called mums or chrysanths, are flowering plants of the genus Chrysanthemum in the family Asteraceae. They are native to Asia and northeastern Europe. Most species originate from East Asia and the center of diversity is in China. Countless horticultural varieties and cultivars exist. The name chrysanthemum is derived from the Ancient Greek: chrysos and Ancient Greek: anthemon. The genus once included more species, but was split several decades ago into several genera, putting the economically important florist's chrysanthemums in the genus Dendranthema. The naming of these genera has been contentious, but a ruling of the International Botanical Congress in 1999 changed the defining species of the genus to Chrysanthemum indicum, restoring the florist's chrysanthemums to the genus Chrysanthemum. Genera now separated from Chrysanthemum include Argyranthemum, Glebionis, Leucanthemopsis, Leucanthemum, Rhodanthemum, and Tanacetum. Wild Chrysanthemum taxa are herbaceous perennial plants or subshrubs. They have alternately arranged leaves divided into leaflets with toothed or occasionally smooth edges. The compound inflorescence is an array of several flower heads, or sometimes a solitary head. The head has a base covered in layers of phyllaries. The simple row of ray florets is white, yellow, or red; many horticultural specimens have been bred to bear many rows of ray florets in a great variety of colors. The disc florets of wild taxa are yellow. Pollen grains are appropriately 34 microns.The fruit is a ribbed achene. Chrysanthemums start blooming early in the autumn. This is also known as favorite flower for the month of November. Chrysanthemums were first cultivated in China as a flowering herb as far back as the 15th century BC. Over 500 cultivars had been recorded by 1630. By the year 2014 it was estimated that there are now over 20,000 cultivars in the world and about 7,000 cultivars in China. The plant is renowned as one of the Four Gentlemen in Chinese and East Asian art. The plant is particularly significant during the Double Ninth Festival. Chrysanthemum cultivation began in Japan during the Nara and Heian periods, and gained popularity in the Edo period. Many flower shapes, colours, and varieties were created. The way the flowers were grown and shaped also developed, and chrysanthemum culture flourished. The Imperial Seal of Japan is a chrysanthemum and the institution of the monarchy is also called the Chrysanthemum Throne. A number of festivals and shows take place throughout Japan in autumn when the flowers bloom. Chrysanthemum Day is one of the five ancient sacred festivals. It is celebrated on the 9th day of the 9th month. It was started in 910, when the imperial court held its first chrysanthemum show. Chrysanthemums entered American horticulture in 1798 when Colonel John Stevens imported a cultivated variety known as 'Dark Purple' from England. The introduction was part of an effort to grow attractions within Elysian Fields in Hoboken, New Jersey. Modern cultivated chrysanthemums are showier than their wild relatives. The flower heads occur in various forms, and can be daisy-like or decorative, like pompons or buttons. This genus contains many hybrids and thousands of cultivars developed for horticultural purposes. In addition to the traditional yellow, other colors are available, such as white, purple, and red. The most important hybrid is Chrysanthemum x morifolium, derived primarily from C. indicum, but also involving other species. Over 140 cultivars of chrysanthemum have gained the Royal Horticultural Society's Award of Garden Merit. Chrysanthemums are divided into two basic groups, garden hardy and exhibition. Garden hardy mums are new perennials capable of wintering in most northern latitudes. Exhibition varieties are not usually as sturdy. Garden hardies are defined by their ability to produce an abundance of small blooms with little if any mechanical assistance, such as staking, and withstanding wind and rain. Exhibition varieties, though, require staking, overwintering in a relatively dry, cool environment, and sometimes the addition of night lights. The exhibition varieties can be used to create many amazing plant forms, such as large disbudded blooms, spray forms, and many artistically trained forms, such as thousand-bloom, standard, fans, hanging baskets, topiary, bonsai, and cascades. Chrysanthemum blooms are divided into 13 different bloom forms by the US National Chrysanthemum Society, Inc., which is in keeping with the international classification system.