A walnut tree ( Juglans regia ) is a species that
belongs to the walnut family or Juglandaceae, containing about
59 species , all them showing pinnate leaves and flowers belonging
to a single sex although in the same tree . Of all them, the
most widely known is the common walnut. It can attain 30 meters
high. Leaves till 25 long, divided in 7 or 9 leaflets with a
sinuate edge.
Flowers greenish . The male ones in form of hanging catkins
till 15 cm of longitude; the female ones , solitary or in spikes
in groups of four. The fruits are called walnuts, although they
are not properly nuts, but drupes
with an edible inside.
Native
from Asia Minor and from the southeast of Europe, it can grow
in the wild in some places in Caucasus and Armenia. Cultivated
species can be easily found in temperate areas in Europe , Asia,
Africa and North America , being California in USA where the
production is the biggest. It can be found from
sea level until more northern areas in the humid temperate forests,
where it could share a natural vegetation with other trees such
as pines, oaks or beeches. Its level of tolerance to a extreme
climate is so wide that some walnut varieties can almost reach
3000 meters high in the mountains of Himalaya. (The common walnut
tolerates temperatures down to -17 ºC).
Varieties
of walnut trees
Many cultivated
varieties exist. Among all we could mention
the following ones:
-
Saint John, Pacana ( Spanish varieties)
-
Chico o Pedro ( Californian)
-
Parisienne ( French variety)
-
Sorrento ( Italian variety )
-
North down ( English variety)
Broadly well-known for its fruits, the common walnut also
highlights for its wood, This has a reddish color and it
is frequently used in joinery, being a species that possesses
a very easy to work wood but, at the same time, very resistant
to rot. It was traditionally used to carry out saints or virgins'
sculptures , as well as decorations of altarpieces and seats
in churches and cathedrals. In the XVI century it took the place
of the oak in the
realization of luxurious furniture. As a board wood it began
to be used in the XVIII century, together with other pieces
of joinery, as tables, clocks, etc. Still today it is considered
a wood of quality to cover the external part of diverse furniture
or to decorate dashboards of high standing cars or ships.
Besides
the species of common walnut ( Juglans regia), we have
other walnut species such as:
-
Black walnut :( Juglans nigra) It is a
species that grows in the East of North America and whose hard
nuts have constituted a good food source for the indigenous
tribes. It is characterized by its big leaves that can reach
till 60 cm long . Its wood is the hardest, reason why it is
much used in buildings, besides in the production of furniture
or ships.
-
Japanese walnut (Juglans ailanthifolia) : With
less height than the previous one, it simply attains 18 meters
high, although its leaves are longer, being able to extend till
80 cm long . Native to Japan, it highlights for its nuts that
are very flavorful and end up in prolonged tip in one of the
ends. Its bark has been used in the dyeing industry.
-
White walnut, butternut ( Juglans cinerea) Coming
from the East of North America, it stands out for its nuts covered
with hair and for its leaves covered with starry hairiness at
the back. Its bark has also been used in the dyeing industry.
