Taxus baccata - Yew tree

Latin plant name Taxus baccata Common plant name Yew tree Plant type Conifer tree  Size (meters) 10 - 20 m Distinguishing features The trunk can be up to 2 metres (exceptionally 4 m) diameter. The bark is thin, scaly brown, coming off in small flakes aligned with the stem. The leaves are lanceolate, flat, dark green, 1–4 centimetres long and 2–3 millimetres broad, arranged spirally on the stem, but with the leaf bases twisted to align the leaves in two flat rows either side of the stem, It is relatively slow growing, and can be very long-lived, with the maximum recorded trunk diameter of 4 metres probably only being reached in about 2,000 years. It is considered by several authors that the oldest yew tree in Spain is located in Bermiego,Asturias. It is known as 'Teixu l'Iglesia' in the Asturian language. It is 15 metres tall with a trunk perimeter of 6 metres and a crown diameter of 10 metres. It was planted around 1160. It was declared Natural Monument on April 27, 1995 by the Asturian Government and is protected by the Plan of Natural Resources. Most parts of the tree are toxic, except the bright red aril surrounding the seed, enabling ingestion and dispersal by birds. The major toxin is the alkaloid taxane. The foliage remains toxic even when wilted or dried. Horses have the lowest tolerance, with a lethal dose of 200–400 mg/kg body weight, but cattle, pigs, and other livestock are only slightly less vulnerable. Symptoms include staggering gait, muscle tremors, convulsions, collapse, difficulty breathing, coldness and eventually heart failure. However, death occurs so rapidly that many times the symptoms are missed. Fatal poisoning in humans is very rare, only occurring after eating a lot of yew foliage. The lethal dose is reported to be between 50 and 100 grams.The wood is also poisonous. There aren't weeds beneath the yew trees because the roots are also poisonous. In the ancient Celtic world, the yew tree (*eburos) had extraordinary importance; a passage by Caesar narrates that Catuvolcus, chief of the Eburones poisoned himself with yew rather than submit to Rome (Gallic Wars 6: 31).  The yew is often found in churchyards in England, Wales, Scotland, Ireland and France. In Ireland it is called the death tree. Yew is the wood of choice for longbow making; the bows are constructed so that the heartwood of yew is on the inside of the bow while the sapwood is on the outside. This takes advantage of the natural properties of yew wood since the heartwood resists compression while the sapwood resists stretching. In latin the termination 'xus' gives the indication of its use in medicine. Taxol is a medicine use to treat cancer and it is extracter from the yew tree.