This section is from the book "The Standard Cyclopedia Of Horticulture Vol2", by L. H. Bailey. See also: Western Garden Book: More than 8,000 Plants - The Right Plants for Your Climate - Tips from Western Garden Experts.
(Greek, golden flower). Including Pyrethrum. Compositae. Plate XXX. A diverse group of herbaceous and sub-shrubby plants, mostly hardy, and typically with white or yellow single flowers, but the more important kinds greatly modified in form and color, grown in the open or flowered under glass in fall.
Plate XXX. Chrysanthemum. - Two of the florist's types.
Annual or perennial herbs, sometimes partly woody, glabrous or loosely pubescent or rarely viscid, usually heavy-scented: leaves alternate, various, from nearly or quite entire to much dissected: heads many-flowered, terminating long peduncles or disposed in corymbose clusters, radiate (rays sometimes wanting); disk-flowers perfect and mostly fertile; ray-flowers pistillate, mostly fertile, the ray white, yellow, rose-colored, toothed or entire; receptacle naked, flat or convex; involucre-scales imbricated and appressed, mostly in several series, the margins usually scarious: achene of disk- and ray-flowers similar, striate or angled or terete or more or less ribbed, those of the ray-flowers often 3-angled; pappus 0, or a scale-like cup or raised border. - Probably nearly 150 recognizable species, in temperate and boreal regions in many parts of the globe, but mostly in the Old World.
The genus Chrysanthemum, as now accepted by botanists, includes many diverse species so far as general appearance is concerned, but nevertheless well agreeing within themselves in systematic marks and by these same marks being separated from related groups. The marks are in large part set forth in the preceding paragraph. Bentham and Hooker make twenty-two sub-groups (of which about six include the garden forms), based chiefly on the way in which the seeds are ribbed, cornered, or winged, and the form of the pappus. The garden pyrethrums cannot be kept distinct from chrysanthemums by garden characters. The garden conception of Pyrethrum is a group of hardy herbaceous plants with mostly single flowers, as opposed to the florists' or autumn chrysanthemums, which reach perfection only under glass, and the familiar annual kinds which are commonly called summer chrysanthemums. When the gardener speaks of pyrethrums, he usually means P. roseum. Many of the species described below have been called pyrethrums at various times, but they all have the same specific name under the genus Chrysanthemum, except the most important of all garden pyrethrums, viz., P. roseum, which is C. coccineum.
The feverfew and golden feather are still sold as pyrethrums, and there are other garden species of less importance. The botanical conception of Pyrethrum is variously defined; the presence of a rather marked pappus-border on the achene is one of the distinctions; the pyrethrums are mostly plants with large and broad heads either solitary or in loose corymbose clusters, the rays usually conspicuous and commonly not yellow, and the fruits five- to ten-ribbed. Hoffmann, in Engler & Prantl "Naturlichen Pflanzenfamilien," adopts eight sections, one of them being Tanacetum (tansy) which most botanists prefer to keep distinct.
Although the genus is large and widespread, the number of plants of interest to the cultivator is relatively few. Of course the common garden chrysanthemum, derived apparently from two species, is the most useful. The insect powder known as "pyrethrum," is produced from the dried flowers of C. cinerarisefolium and C. coccineum. The former species grows wild in Dalmatia, a long narrow mountainous tract of the Austrian empire. "Dalmatian insect powder" is one of the commonest insecticides, especially for household pests. C. cinerariaefolium is largely cultivated in France. C. coccineum is cultivated in California, and the product is known as buhach.
There are over one hundred books about the garden chrysanthemum, and its magazine literature is probably exceeded in bulk only by that of the rose. It is the flower of the East, as the rose is the flower of the West.
Aside from oriental literature, there were eighty-three books mentioned by C. Harman Payne, in the Catalogue of the National Chrysanthemum Society for 1896. Most of these are cheap cultural guides, circulated by the dealers. The botany of the two common species has been monographed by W. B. Hemsley in the Gardeners' Chronicle, series III, vol. 6, pp. 521, 555, 585, 652, and in the Journal of the Royal Horticultural Society, vol. 12, part I. The great repositories of information regarding the history of the chrysanthemum, from the garden point of view, are the scattered writings of C. Harman Payne, his "Short History of the Chrysanthemum," London, 1885, and the older books of F. W. Burbidge and John Salter. For information about varieties, see the Catalogues of the National Chrysanthemum Society (England) and the Liste Descriptive, and supplements thereto, by O. Meulenaere,
Ghent, Belgium. There are a number of rather expensive art works, among which one of the most delightful is the "Golden Flower: Chrysanthemum," edited by F. Schuyler Mathews, Prang, Boston, 1890. "Chrysanthemum Culture for America," by James Morton, Clarksville, Tenn., published in New York in 1891, was the first authentic American work. Within the past few years have appeared "The Chrysanthe-m um, " by Arthur Herring-ton, "Smith's Chrysanthemum Manual," by Elmer D. Smith, and recently "Chrysanthemums and How to Grow Them," by I. L. Powell.