TULIPS (35-38)
[Bulbils.]—These are vegetative growths—neither seeds, bulbs, nor offsets—that appear in the axils of the aërial leaves, as shown in the sketch. Many Liliums, like bulbiferum, tigrinum, speciosum, Leichtlini, and some of the Alliums produce them with great regularity. It is thought that bulbils are borne by some plants and not others, because the conditions for the fertilisation or ripening of the seeds are not favourable. In such cases, therefore, Nature has provided such plants with this means of reproduction by bulbils, rather than allow them to run the risk of dying out altogether. In Kerner and Oliver's "Natural History of Plants" it is stated that "There are two forms of Orange Lily indigenous to Europe. One (Lilium croceum), occurring especially in the Pyrenees and South of France, almost always ripens fruits and forms no bulbils in its leaf-axils. The other (Lilium bulbiferum), found in the valleys of the Central and Northern Alps, hardly ever fruits, but is characterised by the bulbils it produces in the axils of its leaves; bulbils which disarticulate in autumn and are scattered by the wind. But there is no difference noticeable in the structure of the flowers in these two Orange Lilies, and it is difficult to explain their difference in mode of propagation, save on the assumption that in the regions where Lilium bulbiferum grows those insects are wanting which should convey its pollen from flower to flower. As the Orange Lily possesses no arrangements for autogamy (i.e., self-fertilisation), no fruits are formed in the absence of insect visits. It appears that this plant has lost the capacity for autogamy; at any rate, if a stigma be pollinated with pollen from the same flower on plants in a garden, no result follows. On the other hand, offshoots in the form of numerous bulbils are produced by Lilium bulbiferum, by means of which it is propagated and dispersed. In several valleys of the Central Alps it does not flower at all, and thus obviously depends entirely upon its bulbils for propagation."
Bulbils in leaf-axils.
The bulbils should not be detached from the stems until the latter are quite ripe, and the foliage shows signs of withering. They may be sown as if they were large seeds. They possess the advantage over seeds, however, inasmuch as they produce flowering bulbs two or three seasons before the bulbs from real seeds come to maturity.
Tulip Seedling. b. young bulb; r. first root; s. l. seed leaf; s. c. seed-coat.
Bulbous Plants from Seeds.—The would-be raiser of bulbous plants from seeds must be gifted with a good deal of patience, and be systematic in his methods, otherwise he will find it is no sinecure to wait from five to ten years before a flower appears from the seeds he sowed at the beginning of those periods. Even when the blossoms do appear, the great majority of them are likely to be inferior in almost every way to their progenitors. The raising of bulbous plants from seeds, therefore, is not likely to find many enthusiastic disciples among amateur growers, who, as a rule, are content to cultivate the varieties that have been evolved by generations of gardeners. Under these circumstances it is most fortunate that bulbous plants can be so readily multiplied by offsets. Of course, in large gardens and nurseries, where there is a trained staff of men, it is a comparatively easy matter to save and sow a certain quantity of seeds each year. After the first period of waiting is over, each season sees a fresh lot of seedlings burst into blossom. Any particularly fine forms are marked, and afterwards increased by means of the offsets or bulbils.
The annexed drawing shows a seedling Tulip. The germination is very similar to that of the common garden Onion. The swollen portion at the base represents the first stage in the development of the bulb, and each year for six or seven seasons sees it increase in size, and ultimately large and strong enough to blossom.