The bark and shoots of yellow birch give off a strong smell of wintergreen when rubbed or crushed. The trunk is yellowish or silver-grey, without much tendency to peeling. The long leaves are noticeably larger than either of the two Finnish species, and resemble hornbeam (Carpinus) leaves, lying along the branches in layers. This is a showy species, especially in its autumn colour, when it gleams in the sunshine like a raised group of yellow azalea.
The colourful red maple is native to the eastern parts of North America in moist rich broadleaf and mixed forests along waterways. It is also a valued park tree with several selected forms and cultivars in America. The species blossoms with red flowers before the leaves break, these being at first reddish, with silvery or blue-grey undersides. New shoots are also red. Autumn colours are showy, from golden yellow through orange and scarlet to a deep purplish red. For best colour it prefers full sun.
The hemlock (Tsuga) genus gets its scientific name from the Japanese word tsuga. The northern Japanese hemlock is one of the two hemlock species native to Japan, and its natural habitat is the mountains of Honshu Island between 900-2200 metres, approaching the tree line. On the best sites it reaches heights of 25 metres but higher up the slopes remains a low shrub. Compared with other hemlocks the crown is exceptionally dense and broad, reminiscent of broadleaf trees. On their undersides the needles are strongly silver-white, of varying length, broad and notched at the tip.
Olga Bay larch is native to North Korea and neighbouring areas where the climate is similar to Finland’s. Fast-growing, hardy, and beautiful, it grows well in southern and central Finland. Unfortunately, it has so far been planted almost solely in scientific collections. Significant characteristics in identifying the species are the slightly upward-growing branches, very short needles and the cones, which are shiny red before ripening.
Western larch is native to a restricted area in the western Rockies in North America. In Finland it grows successfully only in the richest and warmest sites in the south of the country.
It is most easily distinguished from other larches by its cones, where the seed bracts extend beyond the cone scales. It is narrower in habit than the other larches and large-growing, achieving heights of 40-50m.
The massive, majestic form of the needle fir clearly distinguishes it from other firs at Mustila. It has rough bark, long slightly upswept strong branches and stiff sharp-pointed needles of a lively green. Its timber is durable and a rich dark brown.