Thông ba lá [Vietnamese]; 思茅松 ka xi song [Chinese]; Benguet pine, Khasi pine.
Tree 30-35 m tall with straight, cylindrical bole. Bark thick, dark brown, with deep longitudinal fissures. Branches robust, red brown from the second year, branches pointing downwards. Leaves dark green, soft, at tip of a short twig, usually 3 per fascicle, 15-20 cm long, fascicle 1.2 cm long and persistent. Cones ovoid, 5-9 cm long, often curved downwards, sometimes slightly distorted; scales of second-year cones dense, umbo a little convex, sometimes acutely spinous. Two relief-lines (transverse and longitudinal) across the middle of the scale surface. Seed winged, 1.5-2.5 cm long. Flowers in April-May; fruits 2 years after (FIPI 1996).
India; Thailand; Myanmar; Laos; China: Xizang, Yunnan; Vietnam: Lai Chau, Lang Son, Cao Bang, and Quang Ninh; Philippines. Usually grows pure stands or mixed with broad-leaved trees, but does not form open pine forests. Shade intolerant. Climate wet, subtropical, with a distinct dry and rainy season, humidity not less than 70%. Can grow on poor soils if well-drained. Natural regeneration strongest on mineral soils (FIPI 1996). Hardy to Zone 9 (cold hardiness limit between -6.6°C and -1.1°C) (Bannister and Neuner 2001).
P. kesiya var. yunnanensis is confined to China (Silba 1986).
In the Philippines, it is the dominant species of the Luzon Tropical Pine Forests. This very wet area (over 2,500 mm rain per year) nonetheless has a November-April dry season during which fire is common, maintaining pine dominance in the forest. Red crossbill (Loxia curvirostra), a seed-eating songbird known primarily from high-latitude coniferous forests, reaches its southernmost extent in the Old World in these forests, where it subsists largely on the seeds of Pinus kesiya.
"Timber soft and light. ... Can be used for housing implements, boxes, matches, paper pulp and temporary electric poles. Resin good but not abundant, therefore not yet much exploited" (FIPI 1996).
In the Philippines, the resin provided an important commercial source of turpentine during the Spanish colonial period (Heaney and Regalado 1998).
Listed as threatened in Vietnam by the World Conservation Monitoring Centre.
Heaney, L.R., and J.C. Regalado, Jr. 1998. Vanishing Treasures of the Philippine Rain Forest. Chicago: The Field Museum.
Royle ex Gordon. 1840. Report on the new Species and Varieties of Hardy Trees and Shrubs raised in the Horticultural Society's Gardens since the last Report, made in October, 1838, and published in the "Gardener s Magazine" vol. xiv. p. 581. The Gardener's magazine and register of rural & domestic improvement, January, p.8. Available: www.biodiversitylibrary.org/item/100825, accessed 2011.05.20.
Luu and Thomas 2004 provide a recent description, range map, conservation status, drawings and photos, and a wealth of additional information.
Last Modified 2012-11-23