Pinus nigra, the Austrian pine or black pine, is a moderately variable species of pine, occurring across southern Mediterranean Europe from Spain to the eastern Mediterranean on Anatolian peninsula of Turkey and on Corsica/Cyprus, including Crimea, and in the high mountains of the Maghreb in North Africa.
Pinus nigra is a large coniferous evergreen tree, growing to 20–55 metres (66–180 ft) tall at maturity. The bark is grey to yellow-brown, and is widely split by flaking fissures into scaly plates, becoming increasingly fissured with age. The leaves (“needles”) are thinner and more flexible in western populations (see ‘Taxonomy’ section below).
The ovulate and pollen cones appear from May to June. The mature seed cones are 5–10 cm (rarely to 11 cm) long, with rounded scales; they ripen from green to pale grey-buff or yellow-buff in September to November, about 18 months after pollination. The seeds are dark grey, 6–8 mm long, with a yellow-buff wing 20–25 mm long; they are wind-dispersed when the cones open from December to April. Sexual maturity is reached at 15–40 years; large seed crops are produced at 2–5 year intervals.
Pinus nigra is moderately fast growing, at about 30–70 centimetres (12–28 in) per year. It usually has a rounded conic form, that becomes irregular with age. The tree can be long-lived, with some trees over 500 years old. It needs full sun to grow well, is intolerant of shade, and is resistant to snow and ice damage.
The species is divided into two subspecies, each further subdivided into three varieties. Some authorities (e.g. Flora Europaea) treat several of the varieties at subspecific rank, but this reflects tradition rather than sound taxonomy, as the distinctions between the taxa are small.
- P. nigra subsp. nigra in the east of the range, from Austria, northeast and central Italy, east to the Crimea and Turkey. Needles stout, rigid, 1.5–2 mm diameter, with 3–6 layers of thick-walled hypodermal cells.
- P. nigra subsp. nigra var. nigra (syn. Pinus nigra var. austriaca, Pinus nigra subsp. dalmatica) (Austrian pine): Austria, Balkans (except southern Greece).
- P. nigra subsp. nigra var. caramanica (Turkish black pine): Turkey, Cyprus, southern Greece.
- P. nigra subsp. nigra var. italica (Italian black pine): central Italy (Villetta Barrea, in Abruzzo National Park)
- P. nigra subsp. nigra var. pallasiana (syn. Pinus nigra subsp. pallasiana) (Crimean pine): Crimea.
- P. nigra subsp. salzmannii in the west of the range, from southern Italy to southern France, Spain and North Africa. Needles slender, more flexible, 0.8–1.5 mm diameter, with 1–2 layers of thin-walled hypodermal cells.
- P. nigra subsp. salzmannii var. salzmannii (Pyreneean pine): Pyrenees, Southern France, Northern Spain.
- P. nigra subsp. salzmannii var. corsicana (syn. Pinus nigra subsp. laricio, Pinus nigra var. maritima) (Corsican pine): Corsica, Sicily, Southern Italy.
- P. nigra subsp. salzmannii var. mauretanica (Atlas Mountains black pine): Morocco, Algeria.
In the United Kingdom, Pinus nigra is important both as a timber tree and in plantations (primarily Corsican pine subsp.). Recently however, serious problems have occurred with red band needle blight disease, caused by the fungus Dothistroma septosporum, resulting in a major recent decline in forestry planting there. The timber of European black pine is similar to that of Scots pine (Pinus sylvestris) and red pine (Pinus resinosa), being moderately hard and straight-grained. It does however tend to be rougher, softer, and not as strong, due to its faster growth. It is used for general construction, fuel, and in paper manufacture. (Pinus resinosa, known as red pine or Norway pine, is a pine native to North America.)
In London and the UK the tree is planted as an ornamental tree in parks and gardens. In the UK most of the specimens planted are from Austrian sources, the Pinus nigra subsp. nigra and Pinus nigra subsp. nigra var. nigra seed selections. In the late 1950s and early 1960s, when demand for natural trees was extremely high, its rapid growth, deep green colour and low cost made it briefly a popular Christmas tree, but the extreme length of the needles (making it very difficult to decorate) soon led to its fall from favour.
Edward Step described the Austrian pine as follows. (Pinus laricio, var. austriaca)
What is known as the Austrian Pine is a variety of the Corsican or Larch Pine, and its botanical name correctly set out is Pinus laricio, var. austriaca. The name has reference to the fact that its chief home as an indigenous tree is in the southern provinces of the Austrian Empire. The range of the type and its varieties together includes Central and Southern Europe, and part of Western Asia. It is a comparatively recent addition to our sylva in both forms, for the type was introduced in 1759, in the belief that it was a maritime form of the Scots Pine, but the variety austriaca was first sent out by Lawson and Son, the Edinburgh nurserymen, in 1835.
The typical species (Corsican Pine) is a slender tree of somewhat pyramidal form, growing to the height of 80 to 120 feet. The Austrian Pine, though a large tree, is of smaller proportions—from 60 to 80 feet high—but with stouter and longer branches, and denser foliage. The leaves, which vary from three to five inches in length, are sheathed in pairs, convex on the outer side, rigid, glossy, dark green, and with toothed margins. The cone is conical (!), with a rounded base, two to three inches in length, and its position on the branch is almost horizontal, the scales somewhat similar to those of the Scots Pine, but with stronger bosses, and of a yellowish-brown colour polished. It takes about seventeen months to become full grown and ripen the seeds.
The Austrian Pine is one of those that do well on poor soils, and takes kindly to chalk. From the density of its foliage, it makes a good shade and shelter tree. Its timber, though coarse in grain, is very durable, and useful for outside work.