
Nectar of camellia
Nectar is a
sugar-rich liquid
produced by plants. It is produced either by the
flowers, in which it attracts
pollinating animals or by
extrafloral
nectaries, which provide a nutrient source to animal
mutualists providing
anti-herbivore protection.
It is produced in glands called
nectaries.
Nectar is an economically important item, the sugar source for
honey. It is also useful in
agriculture and
horticulture because the adult stages of many
predatory insects, as well as
hummingbirds and butterflies, feed on
nectar.
Etymology
Nectar is derived from
Latin nectar
"drink of the gods", which in turn has its origins in the
Greek word νέκταρ (
néktar), presumed
to be a compound of the elements
nek- "death" and
-tar "overcoming". The earliest recorded use of its
current meaning, "sweet liquid in flowers", is 1609.
Floral nectaries
Floral nectaries are generally located at the base of the
perianth, so that pollinators are made to brush the
flower's reproductive structures, the
anthers and
pistil, while
accessing the nectar.
Extrafloral nectaries
Nectar produced outside the flower is generally made to attract
predatory insects. These predatory insects will eat both the nectar
and any plant-eating insects around, thus functioning as
'bodyguards'. Extrafloral nectaries are generally located on the
leaf
petioles, mid-rib or leaf
margin. They are thought to be modified
trichomes and exude nectar from
phloem sap. Extrafloral nectaries can be found on
species belonging to (amongst others) the genera
Salix,
Prunus and
Gossypium. In many
carnivorous plants, nectar serves to
attract insect prey.

Extrafloral nactaries on
Prunus
africana
Natural components of nectar
Although its main ingredient is natural sugar (i.e.,
sucrose (table sugar),
glucose, and
fructose),
nectar is a brew of many chemicals.
For example, the nicotiana
attenuata, a tobacco plant native to the US state of Utah
, uses
several volatile aromas to
attract pollinating birds and moths. The strongest such
aroma is benzyl acetone, but the plant also adds bitter
nicotine, which is less aromatic and therefore may
not be detected by the bird until after taking a drink. Researchers
speculate the purpose of this addition is to drive the bird away
after only a sip, motivating it to visit other plants to fill its
hunger, and therefore maximizing the pollination efficiency gained
by the plant for a minimum nectar output. Neurotoxins such as
aesculin are present in some nectars such
as that of the
California
Buckeye.
Other uses of the word
Nectar is a name commonly given to
drinks manufactured with
fruit juice
(e.g. Mango Nectar, Pear Nectar, Peach Nectar).
See also
References
Notes
- Plant-Provided Food for Carnivorous Insects -
Cambridge University Press
- Merbach, M. 2001. Nectaries in Nepenthes. In: C.M.
Clarke Nepenthes of Sumatra and Peninsular Malaysia.
Natural History Publications (Borneo), Kota Kinabalu.
- Nicolson, Susan W.; Nepi, Massimo; Pacini, Ettore
(Eds.), "Nectaries and Nectars", Springer Publications, 2007
p.9)
- Chemical & Engineering
News, Vol. 86 No. 35, 1 Sept. 2008, "Two-Faced Flowers", p.
11
- C.Michael Hogan (2008) Aesculus
californica, Globaltwitcher.com, ed. N. Stromberg
Bibliography
External links