The Swiss Pine or Arolla Pine (Pinus cembra; family Pinaceae) is a species of pine tree that occurs in the Alps and Carpathian Mountains of central Europe, in Switzerland, France, Italy, Austria, Slovenia, Slovakia, Ukraine and Romania. It typically grows at (1,200-) 1,500-2,200 (-2,300) m altitude. It often reaches the alpine tree-line in this area. The mature size is up to 25-35 m height, and 1.5 m trunk diameter.

It is a member of the white pine group, Pinus subgenus Strobus, and like all members of that group, the leaves ('needles') are in fascicles (bundles) of five, with a deciduous sheath. They are 5-9 cm long. Swiss Pine cones are 4-8 cm long. The 8-12 mm long seeds have only a vestigial wing and are dispersed by Spotted Nutcrackers.

The very similar Siberian Pine (Pinus sibirica) is treated as a variety or subspecies of Swiss Pine by some botanists. It differs in having slightly larger cones, and needles with three resin canals instead of two in Swiss Pine.

Like other European and Asian white pines, Swiss Pine is very resistant to White Pine Blister Rust (Cronartium ribicola). This fungal disease was accidentally introduced from Europe into North America, where it has caused severe mortality in the American native white pines in many areas, notably the closely related Whitebark Pine. Swiss Pine is of great value for research into hybridisation and genetic modification to develop rust resistance in these species.

Swiss Pine is a popular ornamental tree in parks and large gardens, giving steady though not fast growth on a wide range of sites where the climate is cold. It is very tolerant of severe winter cold, hardy down to at least -50°C, and also of wind exposure. The seeds are also harvested and sold as pine nuts.

External links

• Pinus cembra cone pic (scroll to bottom of page) (http://www.pinetum.org/cones/PNStrobus.htm)
  
• Photos of Pinus cembra in Switzerland (http://www.pinetum.org/sp/Aletsch.htm)
  
• Gymnosperm Database - Pinus cembra (http://www.botanik.uni-bonn.de/conifers/pi/pin/cembra.htm)