The yew genus (Taxus) includes 8 species which are very similar in habit and in characteristics. They are all poisonous, slow-growing evergreen shrubs or trees which live long. They are all dioecious, i.e. the male plants produce pollen, while the separate female plants develop red berry-like cones in autumn, which are in fact naked seeds almost totally enclosed in a fleshy red aril.
In Finland the hardiest of the genus - and certainly the most planted in the 1900s - is the Japanese yew, which is native to the moist, fertile, mixed and conifer forests of eastern Asia. It is usually shrub-like in form but can grow into a tree up to 15 metres, with long, spreading, up-turned branches, like so many Far Eastern conifers. The needles are a paler green than those of the European yew (Taxus baccata).
The Scot Robert Fortune brought the Japanese yew to Europe in the 1860s. Hardier than the European species, it became very popular. The first seeds of Japanese yew came to Mustila in 1906 from the Kii Peninsula of Central Honshu Island in Japan. The plants grown from these seeds are now tree-like in habit, and can be seen on the west side of the stream running through Tammimetsä (Oak Forest). Other provenances have been tried later throughout the Arboretum, and they all grow more successfully than the European species.