Agriculture Reference
In-Depth Information
4
(b)
(a)
Figure 4.11
Monocotyledonous angiosperms: (a) a
fragrant orchid (
Gymnadenia conpsea
); (b) a bamboo
erinus
or
Erysimum cheiri
(wallflower)
may be grown
as annuals or biennials that are removed and replaced
after their first or second season of growth. These
may be referred to as 'annuals' and 'biennials' by
horticulturists - an example of where botany and
horticulture disagree!
A distinction can also be made between the different
types of woody plants such as trees and shrubs.
Another classification can be made based on a plant's
temperature tolerance, separating those plants that
are able to withstand a frost (hardy), those that cannot
(tender) and those which can withstand a few degrees
of frost but may need some winter protection (half-
hardy). Plants can be grouped according to their degree
of hardiness and various scales are available; the one
in Table 4.2 is produced by the Royal Horticultural
Society (RHS). It must be remembered that, while
withstanding cold conditions is the main factor in a
Figure 4.12
A dicotyledonous angiosperm: rose
fl ower with fi ve petals and a succulent fruit (hips)
