Читать книгу Asparagus, its culture for home use and for market - F. M. Hexamer - Страница 8
BOTANY
Оглавлениеhe genus Asparagus belongs to the Lily Family. It comprises about one hundred and fifty species, and these are spread through the temperate and tropical regions of the Old World. One-half of these species are indigenous to South Africa, and it is from this region that the most ornamental of the greenhouse species have been obtained.
All the species are perennial, with generally fleshy roots or tubers. The stems are annual in some, perennial in others, most of them being spiny, climbing shrubs, growing to a length of from five to twenty or even fifty feet. The true leaves are usually changed into spines, which are situated at the base of the branches and are often stout and woody. The false leaves, termed cladodia, are the linear or hair-like organs which are popularly called leaves; they are in reality modified branches. These cladodia are nearly always arranged in clusters at intervals along the branches, and the flowers generally spring from their axils. They usually fall off the hardy species in winter, and they are easily affected by unfavorable conditions in all the species. Most of them flower and fruit freely under cultivation, so that seeds are available for propagation.
FIG. 2—ASPARAGUS PLUMOSUS NANUS