A. turbinellus (turbinate). fl.-heads delicate mauve, disposed in panicles; involucre top-shaped, scales imbricate. Summer and autumn. l. lanceolate, smooth, entire, with fringed margins, somewhat stem-clasping; those of the branchlets awl-shaped. h. 2ft. to 3ft. North America. A very desirable species. See Fig. 182.
A. undulatus (undulated). fl.-heads pale blue. August. l. oblong-cordate, amplexicaul, entire; petioles winged. Stem panicled, hispid. Branchlets one-sided. h. 3ft. North America, 1699.
A. versicolor (various-coloured).* fl.-heads white, changing to purple; scales of involucre shorter than disk. August. l. sub-amplexicaul, broad-lanceolate, sub-serrate, smooth. Stem glabrous. h. 3ft. North America, 1790.
The annuals (Callistemma hortensis), usually known as French, German, or China Asters, are very extensively grown, both for beds and pots, and their diversity and generally compact growth render them almost universal favourites. They require a rich loamy soil, and as the roots are produced near the surface, a mulching of rotten dung will be found most beneficial. Seeds may be raised in a cold frame in March or April, and, when the seedlings are large enough, they must be transplanted into beds from 9in. to 12in. apart each way. If it is desired to have them in pots, they may be removed thence with a good ball of earth adhering just before they commence flowering, liberally watered, and kept lightly shaded from the sun, until root action is resumed. Those kinds required for exhibition purposes should have several of the side shoots removed, so that the whole growing energy of the plant may be centralised into from five to seven flower-heads, by which means fine blooms may be obtained. The dwarf kinds are most valuable for bedding and pots, as the taller kinds frequently require stakes for support. The following are the most important sections:
Betteridge's Prize. Very beautifully formed and brilliantly coloured varieties, unsurpassed for exhibition purposes. As this class has rather a straggling habit of growth, it is less suitable for bedding and borders than many of the others.
Boltze's Miniature Bouquet Pyramidal. Dwarf and elegant, in compact bouquets of six or eight; the truss of flower-heads springs directly from the ground, having only a few leaves at base. Colours very varied. h. 6in. to 8in.
FIG. 183. TRUFFAUT'S PEONY-FLOWERED ASTER.
FIG. 184. TRUFFAUT'S PERFECTION ASTER.
Crown.* Distinct. The central portion, or disk, of the head of flowers is pure white, surrounded by a broad margin of coloured ray florets, such as purple, violet, crimson, rose, &c. Flower-heads large, flat, freely produced. h. 1ft. to 1½ft.
Dwarf Chrysanthemum-flowered.* In size of flower-heads and habit of growth, this surpasses all other dwarf varieties. The flowers are full, Chrysanthemum-shaped, produced in clusters, or bouquets, from ten to twenty in a truss, very delicate and beautiful in colour. h. 1ft.
Dwarf Pyramidal or Dwarf Bouquet. A pretty little class, and extremely floriferous, each plant producing from twenty to fifty heads of bloom. Some of the colours are: Exquisite carmine with white points, white with blue or carmine points, white with salmon centre, &c. h. 1ft.
Improved Imbricate. The best strain of pyramidal Asters with recurved florets; fine regular form of flowers, double to the centre, producing but few seeds. Colours very brilliant. h. 2ft.
Improved Rose. A handsome class, producing a branched head, displaying no less than fifty large double flower-heads, the outer florets finely imbricated, and filled up to the centre when quite open. The colours are of great brilliancy, and of many shades. h. 2ft.
Pompone Goliath.* Flower-heads globular, and florets very closely set. Valuable for bouquets, as the flowers remain intact for a considerable time.
Pyramidal Hedgehog. Singular and unique. Stems upright, and branched; each branch terminated by a single flower-head, which is filled up with quill-like florets. Colours various. h. 1½ft.
Truffaut's Pæony Perfection.* Vigorous upright growers, having large, hemispherical-formed heads of flowers with incurved florets, 4in. across. The colours also are very varied. h. about 2ft. See Figs. 183 and 184.
