Pinus merkusii

Jungh. & de Vriese (de Vriese 1845)

Common names

Mindoro pine, Sumatran pine, Merkus pine; Tusam, Damar Batu, Damar Bunga, Uyam [Indonesian]; tapulau [Tagalog]; 苏门答腊松 [Chinese].

Taxonomic notes

This is one of the 19 species in Pinus subsection Pinus. Type: Indonesia, Sumatra, Aceh, F. W. Junghuhn & W. H. de Vriese 1 (holotype L); this specimen was collected by Junghuhn in 1841 near Sipirok, Tapanuli Selatan (Harahap 2015). Synonyms include Pinus sumatrana Jungh., and P. finlaysoniana Blume nom. illeg.; neither of these are in common use.

Many authorities in older sources treat P. latteri as synonymous with P. merkusii, conflating the differences in distribution and ecology that distinguish the two species.

The two populations in the Philippines were segregated as P. merkusii subsp. ustulata Businský (2008; syn. P. ustulata (Businský) Businský [2014]). Businský (2014) presents morphological, biogeographical and ecological evidence that his P. ustulata is clearly different from both P. latteri and P. merkusii, and cites further morphological evidence from Cooling (1968). Farjon (2010) differs, reducing subsp. ustulata to synonymy with P. merkusii; however he does not explain his rationale for synonymy. No one other than these authors seems to have addressed the question, it has not been investigated using molecular genetics, and published studies of the Philippine populations have thus far not used the name P. ustulata. Also, P. merkusii has a distribution in two highly disjunct areas, Sumatra and the Philippines; these areas are separated by a minimum of 2600 km, most of it open ocean. It is reasonable to expect that these represent genetically distinct populations. Future genetic studies will likely lead to acceptance of ustulata as a valid taxon, although perhaps not at species rank.

Molecular analyses indicate that P. latteri and P. merkusii, both of which are tropical hard pines from southeast Asia, are basal in Pinus subsection Pinus, sister to a clade containing all the other species in the subsection. Molecular clock evidence, although not confirmed in the fossil record, dates the latteri-merkusii clade to later Eocene time, about 40 million years ago, while the division between P. latteri and P. merkusii dates to the Miocene-Pliocene transition, about 6 million years ago. That was a time of climate change featuring a more intense monsoon and perhaps an increase in wildfire-dominated environments, and both P. latteri and P. merkusii are well adapted to these environments (Jin et al. 2021). The molecular work to date seems to have been based on a single specimen from each species, so further study could prompt re-evaluation of their relationship, but at this point they are two morphologically very similar species having distinct distributions and habitats.

Within Sumatra, foresters recognize 3 "strains" that have not been genetically studied, although they do have morphological and chemical differences. The Aceh strain is northernmost, also the most widespread, and mostly occurs at a low elevation of 200-300 m. The Tapanuli strain occurs closer to the equator, at elevations of 1000-1500 m from the Bukit Barisan Mountain to S of Lake Toba. The Kerinci strain occurs S of the equator at 1500-2000 m elevation in the Kerinci Mountains and has the smallest natural range of the 3 strains (Imanuddin et al. 2020).

Description

Tree 30-50(-70) m tall and 60-80(-200) cm dbh with usually a single straight bole level to upcurved branches, the open crown changing from conical to rounded as the tree ages. Bark first brown, thin and flaky; with age becoming thick, rough, gray-brown or reddish-brown, deeply fissured, forming small rounded plates. Twigs stout, glabrous, brown or dark brown. Foliar buds cylindrical, 15-20 mm long, not resinous; cataphylls brown. Leaves dull green, 2 per fascicle, 15-25 cm long, slender, pliant, 1 mm thick, persistent 2 years, margins minutely serrulate, stomata on all surfaces, held by a 12-18 mm persistent sheath; dried leaves 60-90 mg per fascicle (vs. >100 mg in P. latteri). Pollen cones clustered, spirally arranged, erect, cylindrical, 15-25 × 5 mm. Seed cones sub-lateral on new shoots, in 1's and 2's, borne on stout 1 cm peduncles, (5-)6-10(-11) cm long, green ripening orange-brown, oblong-conical with a rounded base before opening, broad-ovoid when fully opened. Cone scales woody, rigid, oblong, ca. 30 × 12-15 mm at mid-cone, with a rhombic, slightly raised apophysis and a prominent transverse keel; umbo dorsal, central, flat, unarmed. Seeds 5-7 × 4.5 mm, with a 20-25 mm long wing (Cooling and Gaussen 1970, Farjon 1984, de Laubenfels 1988). See García Esteban et al. (2004) for a detailed characterization of the wood anatomy.

In naturally-occurring populations, P. latteri and P. merkusii are most easily distinguished by their disjunct ranges: the former species in mainland southeast Asia, the latter in Indonesia (Sumatra, but widely planted in Java and Sulawesi) and the Philippines (local in Luzon and Mindoro). Despite varying reports from different authors, it appears that seedlings of both P. latteri and P. merkusii sometimes have a grass stage (see P. devoniana for details on "grass stage" growth) (Farjon 2010). Morphological markers to distinguish the two taxa are said to include differences in seed weight, needle and cone dimensions, wood density patterns, oleoresin constituents, and tree size and form (Cooling 1968); but it appears that considerable experience with both species is needed to confidently distinguish them, or to correctly identify cultivated plants. See Cooling (1968) for details. Both are easily distinguished from P. kesiya, widely distributed in SE Asia and the Philippines (Luzon), since the latter species has fascicles of 3 needles.

Distribution and Ecology

Indonesia: N & C Sumatra; Philippines: Zambales peninsula on Luzon Is., and Mindoro. The species has also been widely used for plantation forestry and site restoration in S Sumatra, Java, and Sulawesi (Imanuddin et al. 2020), and seems to have naturalized in those areas (iNaturalist data, accessed 2026.08.07). Climate is wet monsoonal, with annual rainfall of up to 3800 mm (in Zambales). P. merkusii has the most southerly distribution of any pine and is the only pine occurring south of the equator, to 2.10° S in the Barisian Range of Sumatra. It is found at elevations of 200-2000 m, usually in open pine woodlands or savannah-like areas that are frequently burned by native peoples. The best-developed forests are to be found around Lake Toba in N Sumatra (Mirov 1967, Farjon 1984, de Laubenfels 1988, Nghia n.d.). See remarks above on the Sumatran strains. In the Philippines, the species occurs at a relatively low elevation of 100 to 500 m (Razal et al. 2004). In the Zambales peninsula it is primarily found on Mt. Tapulao (elevation 2037 m), hence the Tagalog common name.

Distribution data for the hard pines of southeast Asia, i.e., Pinus kesiya, P. latteri, and P. merkusii. Data from GBIF (2026a, 2026b, 2026c). Data have been cleaned to remove duplicates, remove specimens with high location uncertainty, and remove (most) cultivated specimens except in South Sumatra, Java, Borneo and Sulawesi, where P. merkusii is widely cultivated and often naturalized. Symbology is as follows: Orange denotes P. kesiya s.l.; red is P. kesiya var. kesiya; yellow is P. kesiya var. langbianensis; blue is P. latteri; green is P. merkusii. Circles denote reported occurrences without supporting data; diamonds are reported occurrences based on photographs; stars are specimen collections deposited in herbaria; tree icons contain narrative information. Click on any icon for more information.

Zone 10 (cold hardiness limit between -1°C and +4.4°C) (Bannister and Neuner 2001).

The most recent IUCN conservation assessment, in 2012, assessed this species as "Vulnerable" due to ongoing exploitation of natural stands both in Indonesia and the Philippines; also mining is a threat on Mindoro (Philippines). There are also concerns with genetic contamination in areas where plantations are maintained in close proximity to remnant natural populations, and due to selective logging of individuals with good growth and form properties. Also, forest fires are an issue in some areas. Of the three strains, the Kerinci strain is most severely threatened due to severe habitat fragmentation, largely due to habitat conversion for agriculture (Imanuddin et al. 2020). To some extent, natural stands are being replaced with pine plantations. The total area of occupancy is estimated at less than 2000 km², and the subpopulations are extremely fragmented. The species does occur within protected areas in both Sumatra and the Philippines.

Potential effects of climate change have been investigated using a niche modeling approach, and indicate some range shifts toward higher elevations, but generally no loss of habitat, depending upon the climate scenario and timeframe (Sulton et al. 2024).

P. merkusii, like the rest of the Pinaceae, has an ectomycorrhiza. The primary fungal genera involved are Amanita, Astraeus, Russula, Lactarius, Boletus, Suillus, Lepiota, Thelepora, Scleroderma, and Pisolithus, while still other fungal associates have substituted in pine plantations outside the species' native range (Imanuddin et al. 2020).

Remarkable Specimens

Trees have been reported to 70 m tall (de Laubenfels 1988), which would make it one of the tallest pines in the Old World (the tallest is P. bhutanica). However this is an old and vague record; I have seen no specific height measurements.

Ethnobotany

Little appears to have been published on traditional uses of the species. One source records that the resin and needles of P. merkusii were traditionally used to help treat wounds (Ministry of Health 2017).

Since P. merkusii shows good growth across a wide range of elevations, it has become a strongly preferred species for silviculture in Sumatra, Java and Sulawesi. Since it is also tolerant of dry conditions and poor soils, it is widely used in rehabilitation of degraded lands. This is a product of a long heritage of plantation culture. The state forestry company Perhutani started plantings in Java as early as 1920. In 1927 Dutch forester J. W. Gonggrijp suggested using the species to reforest denuded grassland areas around Karoland and Lake Toba, and the following year large-scale reforestation plantings began near Lake Toba (Harahap 2015). By the mid-1950s silviculture techniques were well-developed (Ferguson 1954, van Alphen de Veer 1953). Today Java has over 9000 km² in plantations, which is about 4 times the extent of all naturally-occurring stands together; this includes 5700 km² in commodity production and 3300 km² in "protection forests"; only teak (Tectona grandis) is planted in a larger area. These Java plantations are primarily derived from trees of the Aceh strain. Similarly, the history of plantations on Sulawesi begins in the 1930s and they now cover about 1650 km². Lesser areas devoted to plantation forestry can be found in Sumatra, Kalimantan, Bali, the Moluccas, and Papua. Overall, the pine forests of Indonesia amount to 14,210 km². These plantations initially focused on restoring degraded lands and on timber production, but over time, the focus has shifted to resin production. There has been considerable effort devoted to developing strains with high resin production and propagating them vegetatively in media inoculated with appropriate ectomycorrhizas (Imanuddin et al. 2020). The Sumatran pine is also used in some innovative agroforestry designs, e.g. "Agroforestry practice by intercropping Sumatran pine with coffee, cloves, and corn or soybeans at the marginal lands in South Sulawesi gives a larger income to farmers than that of a non-agroforestry model" (Imanuddin et al. 2020). The species has also been tested on plantations in Zambia (Nghia n.d.).

Worldwide, pine resin production is much less important today than it was historically, before petroleum derivatives started to take market share that had formerly gone to pine resin products such as turpentine, balsam, tar, and naval stores. The growing market for P. merkusii resins is therefore of particular interest. Imanuddin et al. (2020) summarize the uses of this resin: it is a raw material for the manufacture of gum rosin, soap, adhesives, paints, turpentine oil, and cosmetics. The gum rosin in turn is a raw material for production of paper, ceramics, plastics, paints, batik, soap, printing inks, pharmaceuticals, cosmetics, glues, coatings, and vehicle tires, as well as for the food industry. The turpentine oil in turn is used for disinfectants, fragrance, shoe polish, and synthetic camphor in the metal and wood industry. The demand for these resin-derived products is quite high; around 80% of production is allocated for export to India, Japan, Taiwan, Singapore, Spain, England, Germany, France, Nigeria, and the United States. From 2015 to 2018 pine resin production in Indonesia averaged 116,000 tonnes per year, with a value of about $27 million (US$). Timber production from Sumatran pine was somewhat larger, about 125,000 cubic meters per year, valued at about $33 million. Note that since resin production peaks in trees aged 26 to 50 years, most resin plantations end up being harvested for timber (Imanuddin et al. 2020 and sources cited therein).

Managers of P. merkusii in Indonesia also consider and value other uses of the species, including ecosystem services, support of ecotourism, hydrologic value, employment in surrounding communities, and climate change mitigation and adaptation. These values are detailed by Imanuddin et al. (2020).

In the Philippines, P. merkusii is also used for both resin production and timber production, but in that country these roles are chiefly fulfilled by P. kesiya; in terms of areas planted and economic yield, P. merkusii is a far less important species (Razal et al. 2004 and the IUCN assessment).

This species has been used in dendrochronology to reconstruct long-term trends in monsoonal precipitation (Cook et al. 2010).

Observations

The bulk of observations recorded on iNaturalist are at national parks in Sumatra, notably Kerinci National Park, where you can see the world's southernmost naturally-occurring pines; it is also recorded at Mounts Iglit-Baco National Park, Mindoro, Philippines (Razal et al. 2004).

Detailed observation notes appear in Appendix II of Cooling (1968) although due to the age of this information conditions may have changed considerably.

Remarks

The epithet honors Pieter Merkus who was Governor-General of the Dutch East Indies, and who passed away shortly before this species was described (Harahap 2015).

Citations

Businský, Roman. 2008. The genus Pinus L., pines: contribution to knowledge. A monograph with cone drawings of all species of the world by Ludmila Businská. Acta Pruhoniciana 88:1–126.

Businský, Roman. 2014. The Pinus merkusii agg. (Pinaceae): Literature review, taxa delimitation and typifications. Phyton 54(1):1-26.

Cook, E.R., K.J. Anchukaitis, B.M. Buckley, R.D. D'Arrigo, G.C. Jacoby, and W.E. Wright. 2010. Asian monsoon failure and megadrought during the last millennium. Science 328(5977):486-489.

Cooling, E. N. G. 1968. Pinus merkusii. Fast Growing Timber Trees of the Lowland Tropics No. 4. Oxford, UK: Commonwealth Forestry Institute. Available: https://ora.ox.ac.uk/objects/uuid:299df1a0-cecd-4c2d-ae1f-cb46be6a29e5, accessed 2026.07.18.

Cooling, E. N. G. and H. Gaussen 1970. In Indochina Pinus merkusiana sp. nov. et non P. merkusii Jungh. et De Vriese. Trav. Lab. Forest. Toulouse T.1 V.8 Art. 7.

Ferguson, J. H. A. 1954. Growth and Yield of Pinus merkusii in Indonesia. Netherlands Journal of Agricultural Science 2:197–208.

GBIF.org. 2026a. Pinus merkusii. GBIF Occurrence Download https://doi.org/10.15468/dl.9dksmy.

GBIF.org. 2026b. Pinus latteri. GBIF Occurrence Download https://doi.org/10.15468/dl.yc2df8.

GBIF.org. 2026c. Pinus kesiya. GBIF Occurrence Download https://doi.org/10.15468/dl.wnnjxt.

Harahap, Akhir Matua. 2015. Pohon Tusam (Pinus Merkusii): ditemukan pertama kali di Sipirok oleh Junghuhn tahun 1841 pada era Gubernur Jenderal Pieter Merkus. http://akhirmh.blogspot.com/2015/07/pohon-tusam-pinus-merkusii-ditemukan.html, accessed 2026.08.02.

Imanuddin, R., A. Hidayat, H. H. Rachmat, et al. 2020. Reforestation and Sustainable Management of Pinus merkusii Forest Plantation in Indonesia: A Review. Forests 11:1235.

Jin, Wei-Tao, David S. Gernandt, Christian Wehenkel, Xiao-Mei Xia, Xiao-Xin Wei, and Xiao-Quan Wang. 2021. Phylogenomic and ecological analyses reveal the spatiotemporal evolution of global pines. Proceedings of the National Academy of Sciences 118(20): e2022302118. doi.org/10.1073/pnas.2022302118.

Ministry of Health of the Republic of Indonesia. Directorate General of Pharmaceuticals and Medical Devices. 2017. Reference Materials for Traditional Medicines from Medicinal Plants in Indonesia. Jakarta. p. 631. Available: https://repo.delihusada.ac.id/handle/123456789/551, accessed 2026.08.07

Nghia, N. H. n.d. Pinus merkusii Jungh et de Vriese. APFORGEN fact sheet.

Razal, R. A., M. U. Tolentino, E. S. Garcia, et al. 2004. Status of forest genetic resources conservation and management in the Philippines. Pp. 229-264 in Luoma-aho et. al. (eds.), Forest Genetic Resources Conservation and Management. Proceedings of the Asia Pacific Forest Genetic Resources Programme (APFORGEN) Inception Workshop, Kepong, Malaysia, 15-18 July, 2003. IPGRI-APO, Serdang, Malaysia.

Sulton, Muhammad Nur, Devi Mayang Aurina, Farhan Muhammad, Fariz Pradhana Adil Fadzilah, Zahra Hanun, Muhammad Indrawan, Sugeng Budiharta, Jatna Supriatna, Ilyas Nursamsi, and Ahmad Dwi Setyawan. 2024. Predicting the current and future distributions of Pinus merkusii in Southeast Asia under climate change. Biodiversitas 25(3): 1135-1143. https://doi.org/10.13057/biodiv/d250328.

van Alphen de Veer, E.J., 1953. Plantations of Pinus merkusii as a means of reafforestation in Indonesia. Tectona 43: 119–130.

Vriese, W. H. de. 1845. Plantae novae Indiae batavae orientalis 5, t. 2.

See also

The species account at Threatened Conifers of the World.

Luu and Thomas 2004 provide a recent description, range map, conservation status, drawings and photos, and a wealth of additional information.

Sosef, M. S. M. 1993. Pinus merkusii Junghuhn & de Vriese. In: Soerianegara, I. and Lemmens, R.H.M.J. (Editors): Plant Resources of South-East Asia No 5(1): Timber trees; Major commercial timbers. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea. Contains a more extensive bibliography.