There are therefore fifty-seven distinct species of lilies; but of these there are over one hundred and twenty varieties. Besides these there are four double-flowered varieties, and four definite hybrids.
In our next number we will proceed with the description of these various species and varieties. But before we attempt to describe the individual species, let us glance at some of the chief characteristics of the various parts of lilies.
The lily has two sets of roots. One set develops beneath the bulb, the other is given off by the flower shoot above the bulb. Each set serves a definite purpose, and both are absolutely necessary to the welfare of the plant. The lower roots are concerned chiefly with the development of the bulb; the upper roots, or those given off by the flower-shoot, are the main source of supply to the stem and flowers. Unless these roots develop and are well covered with earth, the plant will not flower.
If the flower stem is removed from the bulb and the upper roots are not disturbed, it will continue to grow unchecked. Or, again, if the bulb be destroyed by disease, or its lower roots do not develop, the lily may still flower; but if the stem roots are destroyed, the shoot dies, even though the bulb and lower roots are quite perfect.
All the lilies possess bulbs. These bulbs are exceedingly characteristic, and differ greatly from those of any other plant. The bulbs of all lilies are imbricate—that is, consist of a number of scales united at their bases.
A typical bulb, such as that of Lilium Longiflorum, consists of numerous scales, closely packed together, united to a firm, fleshy part—the base of the bulb. It is from the base that the lower roots spring. In a perfectly sound fresh bulb the outer scales are approximated to the next layer, but in dry bulbs the outer scales wither and are but loosely applied to the inner ones.
The bulb is narrow at the base, whence it rapidly increases towards the middle, being thickest about one third of the way up from the base. From the middle it rapidly dwindles towards the crown, which usually ends in a point. In the centre of the bulb is the flower spike, which is the densest part of the bulb.
Lily bulbs vary in size, in colour, in shape, and in structure, according to the species. The bulb of Lilium Giganteum is from four to five inches in diameter, whereas that of L. Wallacei is barely half an inch across. As a rule, the larger the plant the larger is its bulb; but this is by no means always the case. The bulb of L. Tigrinum var. Fortunei Giganteum is no larger than that of L. Longiflorum, whereas the former plant is quite three times the size of the latter.
When freshly dug up, most lily bulbs are nearly white in colour; but after exposure to the air for a short time, they get tinted with various shades, which differ remarkably in the different species.
The bulbs of L. Elegans, L. Bulbiferum, L. Croceum, and L. Umbellatum, and others usually remain pure white. L. Longiflorum and a great many others become of a yellowish tint. L. Speciosum and L. Auratum usually become a dark brown or purplish colour. The bulb of L. Giganteum is usually a deep russet colour.