There are around four hundred varieties of willow tree species and they all grow on moist soil, in temperate and colder regions from Europe and North America to Russia and China. Willows can be found even in the arctics, but, in the very cold lands they are very small; one of these tiniest species is called dwarf willow and it doesn't exceed 6 cm in height. Willow tree species are cross fertile, this explains the multitude of hybrids, one of which is the weeping willow so very common in both Europe and North America.
All willow tree variations have a juice rich in water and salicylic acid; this is why, the willow tree is the natural variant of the modern aspirin. Other remarkable chemicals are found in the roots; they are extremely tough and resistant, not to mention that the size and power of life specific to these trees are truly incredible. Willows have both male and female inflorescence, and the catkins appear very early in spring even before flowers. The fruit consist of tiny capsules including a large number of seeds.
Most of the willow tree species can grow from a broken root or old branches, as these trees have an incredible regeneration capacity. They are usually planted on streams to fix the soil better with their huge roots. Various species were planted in Australia to help against water erosion, but after a time it has been noticed that willows practically invaded the watercourses fighting back the local vegetation. Authorities have taken actions against this willow “invasion” and replaced much of the old protective solutions with local alternatives.
The willow tree is mentioned from ancient times in traditional medicine in Assyrian, Sumerian and Egyptian old texts. It is mentioned to effectively fight back aches and fever, Hippocrates mentioned the willow therapeutic properties in the 5th century before Christ, while on the American continent the Amerindians used it with success in their medical treatments. In modern times the acetylsalicylic acid is universally known as aspirin.
In 1763 an English scientist reported to the Royal Society about the benefits this plant had in fighting fever and colds, and later in 1828 a French pharmacist Henri Leroux succeeded in obtaining the acid in it's pure form. The problem was that the pure acid had some side effects at the stomach level so that in 1897 Felix Hoffman obtained the salicin, which was extracted from the Spiraea plant.
Willows are also inspiring for artistic manifestations as many poets used them as a starting point for their creations. The willow tree usually stands for sadness, fragility and the unshared or unfulfilled love, with the poet singing his or her owe to nature.