Range of Pinus greggii (Farjon and Styles 1997).
View of the site I visited near Cerro Potosí. The visible pines are almost all P greggii, and the detail photos below are all from the mature tree at lower left [C. J. Earle, 2007.02.20, waypoint 354].
Bark on the above tree ,which is 35 cm diameter [C. J. Earle, 2007.02.20].
Branch with cone and foliar units [C. J. Earle, 2007.02.20].
Recently matured cones in situ [C. J. Earle, 2007.02.20].
Closed serotinous cone [C. J. Earle, 2007.02.20].
Open cone [C. J. Earle, 2007.02.20].
Typical needle fascicles [C. J. Earle, 2007.02.20].
P. greggii nursery in operation at Dieciocho del Marzo, at the foot of Cerro Potosí [C. J. Earle, 2007.02.20, waypoint 355].
A line of mature trees mark the P. greggii nursery in Dieciocho del Marzo [C. J. Earle, 2007.02.20].
Pinus greggii
Ocote, ocote chino, pino garabatillo, pino garabato, pino prieto (Flores 1996, López-Upton 1996, Perry 1991).
There are two subspecies, the type (treated on this page) and P. greggii var. australis.
NE Mexico (Farjon and Styles 1997). See also Thompson et al. (1999).
Donahue, J.K. and Lopez Upton, Javier. 1996. Geographic variation in leaf, cone and seed morphology of Pinus greggii in native forests. Forest Ecology and Management 82(1): 145-157. Abstract: Pinus greggii Engelm. occurs in two separate regions in Mexico. Northern populations grow in colder, drier climates than southern populations. Southern populations have been shown to grow faster than northern populations in genetic field trials. This study was conducted to determine whether trees from northern populations could be distinguished from southern populations using basic morphological characteristics. Leaf and cone specimens were collected from 177 individual trees of Pinus greggii from 12 native populations, representing a wide ranging sample from both of the two separate regions in Mexico. Twenty leaf, cone and seed characteristics were measured, and discriminant and multivariate analyses of variation performed on the data. Results of the discriminant analyses, using 17 traits, show that the southern populations are morphologically different from the northern populations, and that the southern populations have more variation. In multivariate analyses of variation, seven morphological traits were found to be useful in discriminating northern trees from southern trees: needle length, needle width, number of stomata, number of internal resin canals, seed wing width, seed weight and seed coat thickness. Needle length was the one single trait which distinguished the two groups of populations.
Donahue, J.K. and Lopez-Upton, J. 1995. Seed production of Pinus greggii Engelm. in natural stands in Mexico. Tree Planters' Notes 46(3):86-92. Abstract: Five cones of Pinus greggii Engelm. were collected from each of 117 trees at 12 widely separated sites in Mexico to examine their seed potential and efficiency. Seed efficiency of P. greggii in natural stands was 63% rangewide. Differences were found in seedyield traits related to geographical location. Trees in southern stands in the states of Hidalgo and Queretaro had greater seed potential (117 versus 91 seeds/cone) and produced more filled seeds per cone (74 versus 46) than trees in northern stands in Coahuila and Nuevo Leon. Trees in northern stands had more first-year aborted seeds per cone (42 versus 32) and three times more insectdamaged seeds than trees in southern stands in 1993.
Donahue, J.K., J.P. Perry, A.E. Squillace and S. Liu. 1995. Geographic variation in stem-xylem terpene chemistry in native populations of Pinus greggii Engelm. Forest Genetics 2(4): 217-225. Abstract: Oleoresin samples were collected from 170 individual trees of Pinus greggii from 9 native populations located throughout the species’ natural distribution in Mexico. The samples were analyzed for chemical composition using gas chromatography and GC mass spectrometry. The species in general had high proportions of β-phellandrene and low proportions of α-pinene. The northern populations studied were distinct from southern populations in having lower proportions of α-pinene and myrcene, and higher proportions of limonene and longifolene. Genetic variation in relation to four of the monoterpenes studied was greater in southern populations than in northern populations. Genes affecting the production of the five terpenes studied appeared to be fixed in the northern populations, but only two terpenes tended toward fixation in southern populations.
Dvorak, W. S., J. E. Kietzka and J. K Donahue. 1996. Three-year survival and growth of provenances of Pinus greggii in the tropics and subtropics. Forest Ecology and Management 83: 123-131. Abstract: Eleven provenance/progeny tests of Pinus greggii Engelm. were assessed for survival and height at 3 years of age in Brazil, Colombia and South Africa. Trees of P. greggii from sources in northern Mexico (» 25ºN latitude) were less than half as tall as trees from provenances in central Mexico (» 21ºN latitude) when established in warm climates of Brazil and Colombia, (4.2 m vs. 16 m, respectively). The differences in height growth diminished between southern and northern sources in more temperate climates in South Africa (2.9 m vs. 2.1 m, respectively). External morphological differences in foliage were also pronounced between trees of the two regions when grown as an exotic. Trees from northern sources had shorter, stiffer needles of darker green color than those from southern provenances. The most promising of the southern provenances across all sites were El Madroño (Queretaro) and Laguna Seca (Hidalgo). La Tapona (Nuevo León) and Los Lirios (Coahuila) performed well among the northern sources. Pinus greggii should be tested where low rainfall and cold are considered limiting factors for good growth of P. patula.
Donahue, J.K. and Lopez-Upton, J. 1999. A new variety of Pinus greggii (Pinaceae) in Mexico. SIDA 18(4):1083-1093.
Dvorak, W.S., J.E. Kietzka, and J.K. Donahue. 1996. Three-year survival and growth of provenances of Pinus greggii in the tropics and subtropics. Forest Ecology and Management 83: 123-131.
Dvorak, W.S., J.E. Kietzka, J.K. Donahue, G.R. Hodge, and T.K. Stanger. 2000. Pinus greggii. Pp. 52-73 in Conservation & Testing of Tropical & Subtropical Forest Tree Species by the CAMCORE Cooperative. Raleigh, NC: College of Natural Resources, NCSU.
Dvorak, W.S. 2003. Pinus greggii. Species description in the Tropical Tree Seed Manual. Available http://www.rngr.net/Publications/ttsm/Folder.2003-07-11.4726 (accessed 2007.08.31).
Lopez Upton, Javier; Jasso Mata, Jesus; Vargas Hernandez, J. Jesus; Ayala S, J. Carmen. 1993. Morphological variation in cones and seeds of Pinus greggii. Agrociencia 3(1):81-95 [in Spanish]. Abstract: Morphological variation was studied in cones and seeds sampled at 11 sites of natural range of Pinus greggii Engelm. Significant differences were detected among and within collection sites. Component of variation between trees within sites was the largest. A correlation analysis indicated that cone lenght is positively associated with average annual humidity and temperature of the sites; cone width and seed size are negatively correlated. Cluster analysis provided 5 groups. Even though northern and southern sites were associated, three provenance sites were separated from the principal groups indicating the possibility of being distinct ecotypes.
Lopez Upton, Javier. 2007. HERE is a page with abstracts of all the publications Professor Lopez Upton has produced. About 20 of them deal with Pinus greggii, which I suspect makes him the world authority on this taxon (accessed 2007.08.31).