Pinus martinezii

E.Larsen (1964)

Common names

Ocote, pino (Perry 1991).

Taxonomic notes

Type: Mexico: Michoacán, 4 miles S of Paracho between kilometer markers 45 and 48 on the road from Carapan to Uruapan; 19°17' N, 102° 4' W, elevation 7800 feet, H. V. Hinds & E. Larsen 65, 1960.01.10. Holotype CANB, isotypes MEXU, UC (Larsen 1964). Farjon and Styles (1997) found that the specimen at CANB was absent but that a specimen at FHO was labeled "holotype". Syn: Pinus douglasiana var. martinezii (E. Larsen) Silba 1990.

This species belongs to Pinus subsection Ponderosae. Farjon and Styles (1997) placed it in synonymy with P. durangensis. Larsen (1964) identified some consistent morphological differences from that species, notably the very small deciduous prickle on the umbo (this is often a taxonomically significant character amongst the subsection Ponderosae taxa). Farjon and Styles (1997), having examined the holotype, described the differences as "minor and very inconsistent". Using samples of fresh material collected from 3 locations in Michoacán, Gernandt et al. (2025) found that nuclear DNA placed 2 of these samples sister to a clade comprised of P. arizonica, P. cooperi, P. durangensis, and P. engelmannii. The same study also considered plastome data, in which the 2 samples of P. martinezii grouped together in a clade composed of P. pseudostrobus and P. oaxacana, suggesting that they may have been derived from P. durangensis that captured the plastid of P. pseudostrobus. A third sample of P. martinezii placed within the P. hartwegii-P. montezumae clade for both the nuclear and plastid genomes. This sample was morphologically very close to P. montezumae, introducing some uncertainty as to its identification. Another molecular study incorporated chloroplast microsatellites and ecological niche modeling to compare 307 individuals representing 20 populations of P. durangensis and P. martinezii and found the two taxa to be clearly distinct, independent lineages with different ecological associations, and a disjunct distribution (Contreras-Bailón et al. 2025).

Gernandt et al. (2025) assert P. martinezii warrants recognition as a distinct species and Contreras-Bailón et al. (2025) clearly show it is a distinct taxon from P. durangensis, and has likely been so since the Pleistocene. The evidence supports recognition at species rank.

Description

Trees to 25 m tall and 130 cm dbh, with a sparse rounded crown of thick, horizontal branches that are very rough due to the long-persistent pulvini. Bark brown, thick, scaly, rough, on larger stems developing with deep longitudinal fissures within which is a yellow inner bark. Twigs glaucous and pale green, aging to light brown. Leaves in fascicles of 5–7(–8), 20–28 cm long, stiff, thick, with sharp and serrate margins, and stomata on all faces; in 3–4 rows on the dark green abaxial surface, and in 6–7 rows on the pale glaucous green facial surfaces. In cross section the leaves have two dense but distinct fibrovascular bundles and 3 medial resin canals; the hypodermis often penetrates deep into the chlorenchyma, but rarely reaches the endodermis; outer walls of the endodermis are thick. Fascicle sheath dark brown, aging gray, 12–25 mm long, persistent. Foliage buds conical, pale brown, not resinous. First-year seed cones borne in 1's and 2's, light brown, the scales thick with a small weak prickle, borne on stout scaly peduncles about 12 mm long. Mature seed cones ovoid to conical, subsymmetrical, slightly curved, pale brown, opening when mature in December and January, falling a few months later but leaving the peduncles with a few scales still on the branch. Cone scales hard and strong, about 2.5 cm long and 1.2 cm wide, with a rounded and sometimes uneven apex. Apophysis slightly raised to subpyramidal with a light horizontal keel and rounded apical margin. Umbo dorsal slightly raised, darker than the rest of the apophysis, armed with a small deciduous prickle. Seeds 6 mm long, brown with dark spots, bearing a 12–19 mm wing. Seeds about 48 per gram (Larsen 1964, Perry 1991).

The species generally resembles P. douglasiana but differs in having fascicles of 6 needles (usually), by the very rough bark texture on stem and branches not yet thick enough to develop longitudinal fissures, and by the cones that leave a peduncle and a few scales attached to the branch when they fall. It differs from P. durangensis, the only other 6–needled pine, by having glaucous and relatively long (20–32 vs. 10–22 cm) needles, and by having a small deciduous (vs. strong and persistent) prickle on the umbo (Larsen 1964).

Distribution and Ecology

Mexico: within the western Trans-Mexican Volcanic Belt in Michoacán (Perry (1991); GBIF (2025) also records one specimen from Guanajuato and one from México, out of a total of 14 collections. Perry (1991) also reports its presence in the Sierra de Manantlán of Jalisco, but genetic evidence suggests those trees may be P. durangensis (Contreras-Bailón et al. 2025). A field trip is probably needed to resolve the uncertainty. The known elevation range is 2265–3060 m, in Andisol and Luvisol soils, with annual rainfall of 1000–1500 mm and an average annual temperature of 15.5°C (Leal-Nares et al. 2012, Contreras-Bailón et al. 2025). Frosts are common from December to February (Perry 1991). Commonly associated pines include P. montezumae, P. pseudostrobus, P. teocote, and P. leiophylla (Perry 1991).

Although described in 1964, for most of the period up until 2025 P. martinezii was regarded as a synonym of P. durangensis, so little work was done on it and there were very few collections. However ecological niche modeling in 2025 established that not only is it a species distinct from P. durangensis, but also the two taxa have a disjunct distribution (Contreras-Bailón et al. 2025). This suggests that most specimens labeled "P. durangensis" and collected in Michoacán likely are specimens of P. martinezii. The distributions as determined by ecological niche modeling are shown at right. Ecological niche modeling suggests P. durangensis has a greater tolerance for dry conditions, characteristic of its habitat in the Sierra Madre Occidental, whereas P. martinezii occupies a more southerly, humid environment with generally ample growing season rainfall and relatively low temperature variation. This modeling indicates P. martinezii does best growing on Andisols in areas with a mean annual temperature of 15.0–15.5°C (Contreras-Bailón et al. 2025).

The conservation status of Pinus martinezii has not been formally assessed. The IUCN regards it as synonymous with the much more widespread P. durangensis. Only 6 isolated and fragmented populations are known, and only one of these (Los Azufres, Michoacán) is currently in a protected area. Nonetheless, genetic diversity is high, probably because either the populations were formerly more widespread/continuous or because they are still in close enough proximity to result in appreciable gene flow (Contreras-Bailón et al. 2025). As it seems to have a small area of occurrence and is subject to exploitation for its timber (Leal-Nares et al. 2012), the species appears to be of conservation concern, but the data are not sufficient to assign a risk rating under IUCN criteria.

Remarkable Specimens

I have no data an specific trees, though it's interesting that Larsen (1964) reported sizes to 130 cm dbh, despite visiting only a single site.

Ethnobotany

Wood is strong, soft, not very resinous; harvested for timber and occasionally tapped for resin (Perry 1991).

Observations

I visited the type locality in 2005, only to find it had all been recently logged. Most reported collections have been from that site, but GBIF (2025) reports a 2015 collection from (19.409, -100.157) and 2025 airphotos indicate the area is still well-forested. Six additional collection localities, all in Michoacán, are reported by Contreras-Bailón et al. (2025).

Remarks

The epithet honors Maximino Martínez, eminent Mexican botanist and the first to produce a comprehensive review of the Mexican pines (Martínez 1945). Although, now that we have a Picea martinezii, a Pinus martinezii, P. maximartinezii, and P. maximinoi, literature searches are getting more difficult.

P. martinezii probably arose through vicariance from a P. durangensis-P. martinezii ancestor at the time of the uplift of the Trans-Volcanic Plateau in the late Pliocene, with both taxa subject to further range shifts during the Pleistocene glacial/interglacial fluctuations (Contreras-Bailón et al. 2025).

Citations

Contreras-Bailón, Rubí, Patricia Delgado-Valerio, Alejandra Moreno-Letelier, Daniel Piñero, Ulises Manzanilla-Quiñones, Cuauhtémoc Sáenz-Romero, and Agustín Molina-Sánchez. 2025. Genetic and ecological divergence of Pinus durangensis and Pinus martinezii: two endemic lineages with contrasting evolutionary histories. International Journal of Plant Sciences 186(4). https://doi.org/10.1086/734477.

Farjon, A., and B. T. Styles. 1997. Pinus (Pinaceae). Flora Neotropica Monograph 75. New York, NY: The New York Botanical Garden.

[GBIF] Global Biodiversity Information Facility. 2025. Occurrences returned from the query "Pinus martinezii". https://www.gbif.org/occurrence/search?taxon_key=5285225, accessed 2025.11.11.

Larsen, Egon. 1964. A new species of pine from Mexico. Madroño 17:217–218. Available: Biodiversity Heritage Library, accessed 2025.11.11.

Leal-Nares, Óscar, Manuel E. Mendoza, Diego Pérez-Salicrup, Davide Geneletti, Erna López-Granados, and Eleazar Carranza. 2012. Distribución potencial del Pinus martinezii: un modelo espacial basado en conocimiento ecológico y análisis multicriterio. Revista Mexicana de Biodiversidad 83(4). https://doi.org/10.7550/rmb.27199.

Gernandt, D.S., Willyard, A., Vázquez-Lobo, A., Moreno-Letelier, A., Delgado, P., Figueroa, D.S. and González-Elizondo, M.S. 2025. Multilocus phylogenetics of Pinus subsection Ponderosae using the Hyb-Seq method. Botanical Sciences 103:95–112.

Martínez, M. 1945. Las Pinaceas Mexicanas. Publ. Biol. Univ. Nac. Mexico 16:177–201. Available: https://anales.ib.unam.mx/index.php/anales/article/view/678/623, accessed 2025.10.17.

Perry, Jesse P. 1991. The Pines of Mexico and Central America. Portland, OR: Timber Press. 231 pp.

See also

Morales-Hernández, J., S. Zepeda-Guzmán, J. Cruz-de León, M. Gómez-Romero, and J. E. Ambriz-Parra. 2017. Descripción macroscópica y germinación de semillas de Pinus martinezii Larsen del estado de Michoacán. For. Ver. 19:23–28.

Silva, M. A. 2005. Distribución y aspectos ecológicos de Pinus martinezii Larsen, en el Eje Neovolcánico, Estado de Michoacán, México. BS thesis. Universidad Michoacana de San Nicolás de Hidalgo. Morelia, México.