Agriculture Reference
In-Depth Information
Next year's shoot
Papery scale leaves
Adventitious roots
Axillary bud
Node
Internode
Foliage leaves
surrounding
flower bud
New corm forms
here
7
This year's corm -
swollen stem
storing starch
Last year's corm
Figure 7.18
Structure of a
Crocus
corm
Tendrils
Many plants use modified plant parts called
tendrils which wrap themselves around a
support to climb towards the light. Sometimes
the tendril itself will coil like a spring, pulling the
plant even closer to the support. Tendrils can be
formed from various plant organs and often it
is difficult to establish their origin. In members
of the grape family (Vitaceae), for example,
which includes
Parthenocissus
represented by
P. tricuspidata
(Boston ivy) and
P. quinqefolia
(Virginia creeper),
Vitis vinifera
(grapevine) and
Cissus rhombifolia
(grape ivy), there is much
debate about whether the tendrils are formed
from a leaf, or a stem tip or even a group of
Figure 7.19
Tendrils of passion fl ower
flower buds.
Parthenocissus
have an additional
mechanism in the form of sucker pads on the
