Scotch pine

Scots pine (Pinus sylvestris) is a species of pine that is native to Eurasia, ranging from Western Europe to Eastern Siberia, south to the Caucasus Mountains and Anatolia, and north to well inside the Arctic Circle in Scandinavia. In the north of its range, it occurs from sea level to 1,000 m (3,300 ft), while in the south of its range it is a high altitude mountain tree, growing at 1,200–2,600 m (3,900–8,500 ft) altitude. It is readily identified by its combination of fairly short, blue-green leaves and orange-red bark. The species is mainly found on poorer, sandy soils, rocky outcrops, peat bogs or close to the forest limit. On fertile sites, Scots pine is out-competed by other, usually spruce or broad-leaved tree species. It is the national tree of Scotland. Pinus sylvestris is an evergreen coniferous tree growing up to 35 m in height and 1 m trunk diameter when mature, exceptionally over 45 metres (148 ft) tall and 1.7 metres (5 ft 7 in) trunk diameter on very productive sites, the tallest on record being a more than 210-year-old tree growing in Estonia which stands at 46.6 m (152 ft 11 in). The bark is thick, scaly dark grey-brown on the lower trunk, and thin, flaky and orange on the upper trunk and branches. The habit of the mature tree is distinctive due to its long, bare and straight trunk topped by a rounded or flat-topped mass of foliage. The lifespan is normally 150–300 years, with the oldest recorded specimens in Lapland, Northern Finland over 760 years. The shoots are light brown, with a spirally arranged scale-like pattern. On mature trees the leaves ('needles') are a glaucous blue-green, often darker green to dark yellow-green in winter, 2.5–5 cm (1–2 in) long and 1–2 mm (1⁄32–3⁄32 in) broad, produced in fascicles of two with a persistent grey 5–10 mm (1⁄4–3⁄8 in) basal sheath. On vigorous young trees the leaves can be twice as long, and occasionally occur in fascicles of three or four on the tips of strong shoots. Leaf persistence varies from two to four years in warmer climates, and up to nine years in subarctic regions. Seedlings up to one year old bear juvenile leaves; these are single (not in pairs), 2–3 cm (3⁄4–1 1⁄4 in) long, flattened, with a serrated margin. The seed cones are red at pollination, then pale brown, globose and 4–8 mm (5⁄32–5⁄16 in) diameter in their first year, expanding to full size in their second year, pointed ovoid-conic, green, then grey-green to yellow-brown at maturity, 3–7.5 cm (1 1⁄8–3 in) long. The cone scales have a flat to pyramidal apophysis (the external part of the cone scale), with a small prickle on the umbo (central boss or protuberance). The seeds are blackish, 3–5 mm (1⁄8–3⁄16 in) in length with a pale brown 12–20 mm (15⁄32–25⁄32 in) wing and are released when the cones open in spring 22–24 months after pollination. The pollen cones are yellow, occasionally pink, 8–12 mm (5⁄16–15⁄32 in) long; pollen release is in mid to late spring. Over 100 Pinus sylvestris varieties have been described in the botanical literature, but only three or four are now accepted. They differ only minimally in morphology, but with more pronounced differences in genetic analysis and resin composition. Populations in westernmost Scotland are genetically distinct from those in the rest of Scotland and northern Europe, but not sufficiently to have been distinguished as a separate botanical variety. Trees in the far north of the range were formerly sometimes treated as var. lapponica, but the differences are clinal and it is not genetically distinct.