Picea sitchensis - Sitka spruce

Sitka spruce grows along the west coast of North America from Alaska to California, and has many – sometimes surprising – merits. Few know that it was used in the building of one of the largest aircraft ever, Howard Hughes’ Spruce Goose. This majestic tree has been used throughout history by animals, plants and man.

Malus diversifolia - Oregon crab apple

The Oregon crab is the only North American apple species native to the areas west of the Rocky Mountains. Although it is known to be hardy, it has been grown very rarely in Finland. In America itself the species isn’t regarded as particularly attractive, though the oval shape of the fruit makes it unique among the crab apples. Instead, it is used as root stock for grafting other apple species onto, as it thrives in difficult conditions such as clay or wet. Native Americans used the plant in various ways in their herbal medicines but this use has ceased, so far as is known.

Soldanella montana - Alpine snowbell (mountain snowbell)

The cute little Alpine snowbell is native in the mountains but it thrives also on flatlands. The most crucial prerequisite is sufficient shade. The leaves of the Alpine snowbell are reniform, thick, stiff and evergreen. Conifers provide the best cover especially in spring when deciduous trees are still bare and the sun shines brightly. In sunshine the leaves of the Alpine snowbell become pale and may suffer from brown, dry spots.

Pinus peuce - Macedonian pine

Macedonian pine seeds were first received at Mustila in 1907 from a Bulgarian forester. They had been collected in the Rila Mountains which, despite their southern position, have low average temperatures, and where the snow only melts in June. The species grows in the Balkan mountains as a relict from before the last Ice Age. In addition to Bulgaria and Macedonia, it also grows around Lake Prespa in Albania.

Pinus contorta var. latifolia - (Rocky Mountain) lodgepole pine

Lodgepole pine is native to a narrow belt stretching north-south in the Rocky Mountains of western North America. It is rather narrow-crowned, with needles in bundles of two, distinguishable from the native Finnish species (Pinus sylvestris) by the former’s longer, thicker, twisted and paler green needles. The lodgepole’s bark is thin and dark grey, similar to that of the native Finnish spruce (Picea abies) and lacking the typical orange-red colour and plate-like (in age) bark of Finnish pines.

Pinus cembra subsp. sibirica - Siberian (stone) pine

The Arolla pine (P. cembra) is divided into two subspecies, the Swiss stone pine (P. cembra subsp. cembra) of the central and eastern European mountains, and the Siberian pine (P. cembra subsp. sibirica), which grows over a large range in Siberia, east of the Urals. These subspecies are separated by thousands of kilometres, but to the eye they differ only in the slightly longer cones and the shininess of the buds of the Siberian.

Picea glehnii - Sakhalin or Glehn spruce

The alternative name for this species honours Peter von Glehn, a botanist of German-Baltic origin who worked in Russia. It has a long history at Mustila, having been among the species planted as seedlings from seed sent from Japan in 1908 by the Dane Johannes Rafn, the Arboretum’s ”court purveyor”. The stand, now over 100 years old, is still in fine condition, which can’t be said of many of the exotic spruce planted at Mustila. However, the visitor is more likely to see the Glehn spruce as a young tree, in the 1995 plantings along the Northern Slope road.

Larix hybr. - larch hybrids

The history of larch plantings for timber outside their natural range is a long one. This has lead to the realisation that closely related larch species, when planted close together, can hybridise. Hybrids have also been produced and planted deliberately, often being faster-growing than their parent species. This characteristic is known as heterosis, or hybrid-vigour. The best-known hybrid world-wide is that between the Japanese and European larches (Larix x marschlinsii), known as “Henry’s larch” in Finnish, but Dunkeld or simply Hybrid larch in English.

Abies procera - noble fir

Noble fir is native to a limited area on the Pacific Coast region of North America, growing in the Cascades from the northern border of the state of Washington south to the border between Oregon and California. This is a heavy rainfall area with thick snow cover in winter. Noble fir grows in mixed forest with other conifers. In contrast to most firs, it can live for as long as 300 years.