The Italian city of Venice is built on several small islands. The wet sand is as fluid as soft jelly. You build a house and it sinks in a little while. In order to reinforce the ground the Venetians had rammed hundreds of thousands of wooden piles into it so it would make a solid foundation for the majestic city.

But it is a well-known fact that wood rots in the ground. However, the city of Venice has been standing on its wooden piles since the year 810!

More than one thousand and two hundreds years passed since then, and suddenly the citizens began to wonder: “What if the piles started to rot?”
“How is it that the Venetian piles are so strong?”
Glory be to You, we have no knowledge except what you have taught us. Verily, it is You, the All-Knower, the All-Wise. (The Holy ‘Qur~an  [T.M.Q.] chapter of the Cow, verse 32)

The trunks and branches of the trees are covered with bark. It is like skin on the human being. As long as the bark is whole, the trunk is safe, but once the bark is damaged it lets through the spores of harmful fungi through the wood. Or it is best with bacterial rot which eventually turns the wood to dust. Of course, it is bad when the bark is injured, but that does not mean that the “wounded” wood will not inevitably rot. Much depends on the species of the wood and its ability to protect itself.

When the bark of a coniferous tree is injured, it starts to secrete resin which consists of turpentine and colophony. The acid turpentine kills “enemies” while the sticky colophony puts a healing “bandage” on the wound.

The powder-post beetle causes the forests a lot of damage, but the resin saves the coniferous trees from the pests. Even if a beetle manages to drill him a hole in the tree-trunk, the resin will get him even there and immure him. That is why beetles avoid healthy trees that have plenty of resin. The smell of the turpentine acts on them the same way as a red traffic-light on people.

All trees of coniferous family posses resin, but the Larch is especially rich in it. The abundance of resin makes it remarkably strong. That is why it may be preserved for centuries in wet ground and water.

What is Larch?
Larch or pine has the botanical name: Pinus larox. Its family is coniferae, or coniferous.
Synonyms:-larix Europea. Abies larix deciduas. Laricis Cortex. Meleze. European Larch. Venice Turpentine.

Description:
Larch grows to about 33 feet (10 meters) tall, with brownish bark, horizontal branches, and a thin crown. The leaves, deciduous needles, from fascicles of ten to twenty on short spur branches. The branches are long, very narrow. Slender, and flexible, three-angled and blue-green. Before falling in early autumn they turn yellow. The twigs are long, stout, dull tan, and hairless, with many short stout spur twigs. Winter buds are small and round, about 1/2 inch (2cm) long and covered by many short, pointed, overlapping scales. Rounded, upright female cones measure 2/5  to  3/4 inch (1 to 1.5cm) long.

Constituents:
The bark contains tannic acid, larixinic acid and turpentine. The larixin, a crystalline principle, resembles pyrogallol.
Briancon Manna is exuded from the leaves in summer. It is white and sweet, occurring in oblong tears and almost odourless. Its peculiar sugar is termed Melezitose. Its use is obsolete.

If the trees are burnt, a gum exudes from the trunk called Gummi Orenbergense, soluble in water like Gum Arabic.
Medicinal uses: Larch bark tea is a laxative, tonic, diuretic, alterative. It is useful in obstructions of the liver, rheumatism, jaundice, and some cutaneous diseases (Grieve). She also reports the use of the leaves as a decoction for piles, haemoptysis, menorrhagia, diarrhea, and dysentery.

The inner bark, made into tea, is good for bleeding of any kind, hemorrhoids, excessive menstruation, and as a tonic to the liver and spleen.


References:
1. anken.uaf.edu/viereck/vierecklarch.html
2. 2020site.org/trees/larch.html
3. natural.org/p/pinela35.html
4. beautifulvenice.com