Pinus maximartinezii

Rzedowski 1964

Common names

Martínez piñon (Lanner 1981), maxipiñon [Spanish].

Taxonomic notes

Type: Zacatecas, Sierra de Morones, W of Pueblo Viejo, 1964.01.25, Rzedowski 18258 (holotype, MEXU) (Rzedowski 1964). Although the population is currently critically small, it may have been even smaller in the recent past: "Significant gametic disequilibrium ... at several pairs of loci in both maternal and paternal gametes ... is in agreement with an origin from an extreme bottleneck, perhaps even a single seed. Furthermore, it demands that the event be relatively recent. The number of generations, as calculated from the observed mean disequilibrium, suggested that maxipiñon derived from an extreme bottleneck four to five generations ago, which is less than 1000 years in this species" (Ledig et al. 1999). More recent work by Ledig et al. (2001) suggests that the progenitor species may have been P. pinceana, long recognized as the most closely related species. P. rzedowskii is another near relative.

Description

A tree to 16 m tall and 40 cm dbh (M.P. Frankis, field notes, Nov-1991). Bark smooth pale grey at first, becoming thinly scaly grey-brown on mature trees. Crown broad, with irregular branches. Leaves blue-green, in fascicles of 5, sheath mostly deciduous but the small basal sheath scales persisting; 6-12 cm long, about 0.8-1 mm thick, with white stomatal bands on the inner faces and a glossy green outer face. Cones huge, massive, pendulous on surprisingly slender peduncles 1-3 cm long and only 6-8 mm thick; oval-cylindric, 14-23 (-26) cm long, 10-12 cm broad, green ripening pale brown and opening to 11-14 cm broad; up to 2 kg when green (Perry 1991). Scales massive, 35-50 mm broad, 20 mm thick, apophysis pyramidal, with an unarmed knoblike 10-15 mm wide umbo. Seeds very large, 22-26 mm (the largest of any pine), orange-buff, wing 1-2 mm, vestigial, remaining attached to the scale when seed removed (Rzedowski 1964; M.P. Frankis, field notes, Nov-1991). Seeds do not fall naturally from cone, but are dispersed by birds (Lanner 1981). Cones mature in August, about 27-28 months after pollination (M.P. Frankis, field notes, Nov-1991; from conversations with villagers in Pueblo Viejo), an unusually long period. Seedlings have up to 24 cotyledons on germination (the most of any plant), and continue to produce juvenile foliage only for several years, with nodding white shoots and single 3-4 cm leaves, strongly glaucous.

Distribution and Ecology

Mexico: Durango and Zacatecas. The Zacatecas site was the species' only known locality from its discovery in 1964, until 2010, when a second population was discovered in extreme S Durango (González-Elizondo et al. 2011).

In S Zacatecas, the species is found from ca. 12 km SW to a few km W of Juchipila. It is found in scattered stands across an area of about 5-10 km² on ridges and E-facing slopes of the Sierra de Morones (Farjon and Styles 1997), in montane dry forest at (1800-)1900-2200(-2500) m altitude (Perry 1991, Burkhard Witt email 2006.11.24). These trees represent a single population, numbering approximately 2000 to 2500 mature individuals in an area of 400 hectares (Ledig et al. 1999); thus its status as an endangered species. However, it is actively being protected while contributing to the local economy (as described below), with the result that "all locals I encountered in the field have one aim: the conservation of Pinus maximartinezii" (Burkhard Witt email 2009.02.05). USDA hardiness zone 9.

The S Durango population occurs near the town of La Muralla, occurring at 1750 to 2260 m elevation on steep slopes at various aspects, on lithosols and regosols derived from volcanic rock. The population includes approximately 900 trees in an area of approximately 110 ha, but detailed surveys have not yet been performed on the ground. As in Zacatecas, the trees occur in discontinuous patches on the landscape in a forest dominated by Quercus spp. and Pinus lumholtzii; many understory species are also similar between the two sites (González-Elizondo et al. 2011).

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

Remarkable Specimens

Ethnobotany

The species was discovered when Mexican botanist Jerzy Rzedowski found its exceptionally large and highly edible seeds for sale in a local market. There is probably still some local use of the seeds as food, but Local workers now get an income for collecting the mature cones, for taking the seeds from the cones and for cutting bushes around the piñones to prevent a possible fire from ascending into their crowns. The seeds are no longer used for food but for propagation for reforestation programs. The trees are no longer cut for firewood (Burkhard Witt e-mails 2006.11.24, 2009.02.05). The trees in the Durango population are also used as a source of seed for food (González-Elizondo et al. 2011), although as in Zacatecas, this may change as the local people become more aware of the trees' rarity and value.

Observations

See Perry (1991) for details of access to the Zacatecas population; the best trees with the largest cones grow at higher altitudes on the Sierra; low altitude trees are stunted by drought and only bear smaller cones (M.P. Frankis, field notes, 1991.11). More precise locational evidence has not been published and is not detailed here, in the interests of protecting the species. However, if you wish to see it in habitat in Zacatecas, contact Ing. Isaac Quintero Quintero, González Ortega No. 133, Juchipila, Zac., México, C.P. 99960 (tel. (467) 9-52-05-44 or 9-52-14-28). He can arrange a visit to the trees (Burkhard Witt email 2006.11.24).

Remarks

A very attractive tree. In cultivation, leaves up to 23 cm long may be produced.

This species is listed as endangered by the Mexican government (NOM-ECOL-059-94; also in NOM-059-SEMARNAT 2010). It is reported (Burkhard Witt e-mail 2009.02.05) that the Mexican government, with the full support of the local people, is making every feasible effort to protect this species.

Citations

González-Elizondo, Martha, M. Socorro González-Elizondo, Lizeth Ruacho-González, and Moisés Molina-Olvera. 2011. Pinus maximartinezii Rzed. (Pinaceae), primer registro para Durango, segunda localidad para la especie. Acta Botanica Mexicana 96:33-48.

Ledig, F.T., M.T. Conkle, B. Bermejo, T. Eguiluz, P. Hodgskiss, D.R. Johnson, and W.S. Dvorak. 1999. Evidence for an extreme bottleneck in a rare Mexican pinyon: genetic diversity, disequilibrium, and the mating system in Pinus maximartinezii. Evolution 53(1):91-99.

Ledig, F.T., M.A. Capo-Arteaga, P.D. Hodgskiss, H. Sbay, C. Flores-Lopeez, M.T. Conkle, and B. Bermejo-Velazquez. 2001. Genetic diversity and the mating system of a rare Mexican piñon, Pinus pinceana, and a comparison with Pinus maximartinezii (Pinaceae). American Journal of Botany 88: 1977-1987. Available: http://www.amjbot.org/cgi/content/abstract/88/11/1977, accessed 2009.02.06.

Rzedowski, J. 1964. Una especie nueva de pino piñonero del estado de Zacatecas (Mexico). Ciencias (Mexico) 23: 17-20.

Description prepared by M.P. Frankis, 1999.01.

See also

The species account at Threatened Conifers of the World.

Donahue, J.K. and Carlos Mar López. 1995. Observations on Pinus maximartinezii Rzedowski. Madroño 42(1): 19-25. Available: Biodiversity Heritage Library, accessed 2021.12.19.

Dvorak, W.S., T.K. Stanger, and J.L. Romero. 2000. Pinus maximartinezii. Pp. 95-105 in Conservation & Testing of Tropical & Subtropical Forest Tree Species by the CAMCORE Cooperative. Raleigh, NC: College of Natural Resources, NCSU.

The Nature Conservancy. 1996. Natural Heritage Central Database. (Status and distribution data on Latin American plants, developed in collaboration with Latin American Conservation Data Centers and Missouri Botanical Garden.).

Vovides, A.P. 1981. Lista preliminar de plantas Mexicanas raras o en peligro de extinción. Biotica 6(2): 219-228.