Agriculture Reference
In-Depth Information
Remains of this
year's shoot
Papery outer
scale leaves
enclosing
bulb
Next year's
shoot and
flower with
foliage
leaves
Fleshy food-
storage scale
leaves
Axillary bud
Daughter bulb
forming
from axillary bud
Basal plate
(shortened stem)
Contractile root
Adventitious roots
Figure 7.21
Structure of a
Narcissus
bulb
Phyllodes
, found in
Acacia
spp., are flattened leaf-like
petioles which replace and carry out the functions of
the leaves. The leaves of many monocots are believed
to have originated from phyllodes.
Sedum
, in common
with many plants adapted to arid conditions, have
succulent
fleshy leaves
which are able to store water,
while in the houseplant
Bryophyllum daigremontianum
the succulent leaf bears
adventitious buds
which
are able to drop to the ground below and develop into
young plantlets.
7
Further information on plant adaptations and their use
in propagation are found in Chapter 11 and on the
companion website.
Figure 7.22
White bracts of fl owering dogwood. The
insignifi cant fl owers are in the centre of the bracts
minimizing the risks from extremes of climate, or
pests such as eelworms and mice. Bulbs have both
adventitious and contractile roots (see above) attached
to a basal plate. Daughter bulbs form in the axils of
the leaves which eventually detach, bringing about
vegetative spread.
In many plants such as
Hydrangea
spp
.
, the
houseplant
Euphorbia pulcherrima
(poinsettia) and
flowering
Cornus
spp. (dogwoods) (Figure 7.22)
,
coloured
bracts
take the place of petals in attracting
pollinating insects.
Further reading
Capon, B. (2005)
Botany for Gardeners
. Timber Press.
Hickey, M. and King, C. (1997)
Common Families of
Flowering Plants.
Cambridge University Press.
Hodge, G. (2013)
RHS Botany for Gardeners
. Mitchell
Beazley.
Jepson, M. (1938)
Biological Drawings
. John Murray.
McMillan Browse, P. (1979)
Plant Propagation.
Mitchell Beazley.
Stern, K. (2001)
Introductory Plant Biology.
8th edn.
McGraw Hill
Please visit the companion website for further information:
www.routledge.com/cw/adams
