|
Red nectary of
Coryphantha echinoidea |
Extra-floral nectaries
(areolar glands) are
glands, usually located (in
Cactus) in the
tubercle-grooves or in the
axils.
These nectary-glands exude a viscous
juice ( nectar) with a high
sugar-content and represent a sophisticated
strategy for ant attraction.
|
A drop of nectar
(Glandulicactus
wrightii) |
- The first hypothesis for why plants secrete extra floral nectar is that
the presence of pugnacious ants seems to reduce the vulnerability of
flower buds by herbivores
insect, resulting in greater
fruit production
and tissue survival. (or by decreasing seed predation on plants.)
- The second hypothesis is that they distract ants from foraging at
floral nectaries, this might also serve as an adaptation to reduce ant
visitation to flowers.
- The third hypothesis is the nutrient enhancement. Ant colonies tend to
concentrate nutrients in the immediate vicinity of their nests --
through storing food, discarding debris, and defecating - plant that
bearing extra floral nectar attract ant nests to their
base.
- Moreover ants can play an important rule in
distributing the
seeds of these plant.
In humid conditions, the nectar exudation (if not
completely removed by ants) can cause the formation of mould which leads
to ugly black-colouring of the epidermis. To prevent this, spray off the
plant with water to remove the nectar. And provide a very good
ventilation.
(For example
Coryphantha echinoidea)
- Moreover ants can play an important rule in
distributing the
seeds of these plant.
In humid conditions, the nectar
exudation (if not
completely removed by ants) can cause the formation of mould which leads
to ugly black-colouring of the epidermis. To prevent this, spray off the
plant with water to remove the nectar. And provide a very good
ventilation.
(For example
Coryphantha echinoidea) |
