This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Receptacle naked. Pappus none or cup-shaped. The species are natives of Europe, Asia, and North Africa. The name is from golden, and flowers, but it is only applicable to some species. Some of the species are separated under the name Pyrethrum, from having a cup-shaped membranous pappus. The first name is retained because it is in general use. The Ox-eye Daisy, G. Leucanthemum and the Corn Marigold, C segetum, are two familiar native species.
1. Ch. Sinense, including Ch. Indicum. - These two names designate two tolerably distinct races which are now generally believed to have sprung from one and the same species. However this may be, some of the varieties in cultivation at the present time cannot be referred to one or the other with certainty, and to these has recently been added a third group of varieties from Japan remarkable alike for their ragged grotesque-looking flower-heads and the unusual tints of the flowers. The history of the garden varieties is rather obscure, and the wild form is unknown to botanists, but the later progress in the production of improved varieties is more familiar. In some books we find the year 1784 given as the date of the original introduction of some Chinese variety or varieties. But 1790 is the earliest authentic account we have, at which period it was introduced into France by a merchant named Blanchard; and in 1826 an amateur of Toulouse named Bernet conceived the idea of raising plants from seed, which resulted in the acquisition of some new varieties. This method was soon adopted by other growers, at first in France and subsequently in England, where Chrysanthemums now receive more attention than in any other country. The variety or race called Indicum was imported from China about the year 1835, and this was subjected to the same procedure, and crossed with varieties of the older strain.
We must not omit to mention that, besides the ordinary double flowers of this family, in which the florets are elongated on one side only, there is another form having the disk florets elongated and regularly 5-toothed. Varieties of the latter class were introduced by Fortune. The colours and tints of Chrysanthemums belong to the red, yellow, and orange group, with innumerable intermediate hues and pure white. Florists divide them into Large-flowered (fig. 139) and Small-flowered or Pompon (fig. 140); the former being the type of those first introduced. There are also the Japanese varieties alluded to above, with curious elongated often very narrow florets.
2. Ch. Parthenium (Pyrethrum). Feverfew. - This plant was formerly cultivated as a medicinal herb, and has become naturalised in some parts of the country. It is from 1 to 2 feet high, with the leaves pinnately divided into broad lobed segments. Flowers about 6 lines in diameter with a white ray. We mention this merely to introduce the double-flowered variety, eximium; and one with yellow foliage, aureum, extensively employed in bedding under the name of Golden Feather. 3. Ch. roseum (fig. 141).- This may be classed with the so-called Florists' flowers, having produced a great many beautiful varieties which now figure in our principal catalogues under distinct names. In the typical form it grows about 18 inches high, with beautifully cut foliage and flower-heads about 2 inches in diameter, yellow in the centre, with a rose or pink ray. The disk is large and the ray-florets relatively short. It is a native of the Caucasus. The garden varieties are either single or double, with the florets plain or fringed, white, salmon, pink, rose, crimson, or purple of some shade, or two-coloured. They begin to bloom in May and continue for a long period.
Fig. 139. Chrysanthemum Sinense, large-flowered variety. (1/4 nat. size.)
Fig. 140. Chrysanthemum Sinense, Pompon var. (1/4 nat. size.)
Fig. 141. Chrysanthemum roseum. (1/4 nat. size.)
Fig. 142. Ch. coronarium. (1/4 nat. size.)
4. Ch. Tchihatchewii. - This species is unfortunate in its name, but said to be useful for covering banks. It is a trailing perennial with small bipinnatifid glabrous dark green leaves toothed at the base of the petiole and small white flowers.
5. Ch. coronarium (fig. 142). - A branching annual from 2 to 3 feet high bearing a profusion of single or double yellow flowers, according to the variety. A native of the South of Europe.
6. Ch. carinatum, syn. Ch. tricolor (fig. 143).- Another annual species, superior to the last as an ornamental plant.
Fig. 143. Chrysanthemum carinatum. (1/3 nat. size.)
Foliage glaucous. Flowers normally white and yellow with a brown centre, but there are several improved garden varieties, including double ones, yellow, crimson, or purple, or one of these colours with a brown centre. A native of North Africa.
Dimorphotheca pluvialis, Cape Marigold, is a pretty annual. Leaves narrow, sinuately lobed; florets of the ray white within, violet without; disk brown.
Athanasia annua is a native of Barbary growing about 2 feet high, and valuable on account of the long duration of its clustered rayless yellow flower-heads. Stem furrowed. Leaves fleshy, pinnatifidly divided into linear segments.