The stone pine, botanical name Pinus pinea, also known as the Italian stone pine, Mediterranean stone pine, umbrella pine and parasol pine, is a tree from the pine family (Pinaceae). The tree is native to the Mediterranean region, occurring in Southern Europe and the Levant. The species was introduced into North Africa millennia ago, and is also naturalized in the Canary Islands, South Africa and New South Wales.
Stone pines have been used and cultivated for their edible pine nuts since prehistoric times. They are widespread in horticultural cultivation as ornamental trees, planted in gardens and parks around the world. This plant has gained the Royal Horticultural Society's Award of Garden Merit.[1]
Pinus pinea is a diagnostic species of the vegetation class Pinetea halepensis.[2]
The prehistoric range of Pinus pinea included North Africa in the Sahara Desert and Maghreb regions during a more humid climate period, in present-day Morocco, Algeria, Tunisia, and Libya. Its contemporary natural range is in the Mediterranean forests, woodlands, and scrub biome ecoregions and countries, including the following:
In Greece, although the species is not widely distributed,[3] an extensive stone pine forest exists in western Peloponnese at Strofylia[4] on the peninsula separating the Kalogria Lagoon from the Mediterranean Sea. This coastal forest is at least 8miles long, with dense and tall stands of Pinus pinea mixed with Pinus halepensis.[5] Currently, Pinus halepensis is outcompeting stone pines in many locations of the forest.[6] Another location in Greece is at Koukounaries on the northern Aegean island of Skiathos at the southwest corner of the island. This is a half-mile-long dense stand of stone and Aleppo pines that lies between a lagoon and the Aegean Sea.[7]
The stone pine is a coniferous evergreen tree that can exceed 25abbr=offNaNabbr=off in height, but 12- is more typical. In youth, it is a bushy globe, in mid-age an umbrella canopy on a thick trunk, and, in maturity, a broad and flat crown over 8m (26feet) in width. The bark is thick, red-brown and deeply fissured into broad vertical plates.
The cones are broad, ovoid, 8- long, and take 36 months to mature, longer than any other pine. The seeds (pine nuts, piñones, pinhões, pinoli, or pignons) are large, 2frac=4NaNfrac=4 long, and pale brown with a powdery black coating that rubs off easily, and have a rudimentary 4- wing that falls off very easily. The wing is ineffective for wind dispersal, and the seeds are animal-dispersed, originally mainly by the Iberian magpie, but in recent history largely by humans.
Pinus pinea has been cultivated extensively for at least 6,000 years for its edible pine nuts, which have been trade items since early historic times. The tree has been cultivated throughout the Mediterranean region for so long that it has naturalized, and is often considered native beyond its natural range.
The tree is among the current symbols of Rome.[8] It was first planted in Rome during the Roman Republic, where many historic Roman roads, such as the Via Appia, were (and still are) embellished with lines of stone pines. Stone pines were planted on the hills of the Bosphorus strait in Istanbul for ornamental purposes during the Ottoman period. In Italy, the stone pine has been an aesthetic landscape element since the Italian Renaissance garden period. In the 1700s, P. pinea began being introduced as an ornamental tree to other Mediterranean climate regions of the world, and is now often found in gardens and parks in South Africa, California, and Australia. It has naturalized beyond cities in South Africa to the extent that it is listed as an invasive species there. It is also planted in western Europe up to southern Scotland, and on the East Coast of the United States up to New Jersey.
In the United Kingdom it has won the Royal Horticultural Society's Award of Garden Merit.[9] [10]
Small specimens are used for bonsai, and also grown in large pots and planters. The year-old seedlings are seasonally available as table-top Christmas trees 20- tall.
Other products of economic value include resin, bark for tannin extraction, and empty pine cone shells for fuel. Pinus pinea is also currently widely cultivated around the Mediterranean for environmental protection such as consolidation of coastal dunes, soil conservation and protection of coastal agricultural crops.
The introduced western conifer seed beetle (Leptoglossus occidentalis) was accidentally imported with timber to northern Italy in the late 1990s from western USA, and has spread across Europe as an invasive pest species since then. It feeds on the sap of developing conifer cones throughout its life, and its sap-sucking causes the developing seeds to wither and misdevelop. It has destroyed most of the pine nut seeds in Italy, threatening P. pinea in its native habitats there.[11]
Pestalotiopsis pini (a genus of ascomycete fungi), was found as an emerging pathogen on Pinus pinea in Portugal. Evidence of shoot blight and stem necrosis were found in stone pine orchards and urban areas in 2020. The edible pine nut production has been decreasing in the affected area due to several factors, including pests and diseases. The fungus was found on needles, shoots and trunks of Pinus pinea and also on Pinus pinaster. Pestalotiopsis fungal species could represent a threat to the health of pine forests in the Mediterranean basin.[12]