Pinus greggii
Encyclopedia
Pinus greggii, or Gregg's pine, is a small to medium high pine
tree native to eastern Mexico
, found in two distinct regions. It has an open crown and long and slender branches. The needles are in bundles of three with an average length of 11 cm. The cones are clustered in groups of 5 – 10. The branches en upper trunk is smooth. Pinus greggii is introduced in several countries.
in 1868
Two varieties are found in literature:
The species name greggii honors Josiah Gregg
(1806 – 1850), a merchant, explorer, naturalist, and author of the American Southwest and Northern Mexico.
The bark
remains smooth for a long time in this species, and only old trees have rough bark at the base of the trunk. The bark is thick, with deep, longitudinal fissures and rough, elongated plates. On the upper part of the trunk and branches smooth to finally scaly. Greyish brown.
The crown
is loose and open.The branch
es are long and slender, swaying in the wind, spreading or curved downward, not pendulous, forming a rounded, dense or more open crown. The young twigs are bluish-green.
The winter buds are narrow and sharp pointed, without resin and with loose scales, usually light-brown.
The needles are (7-)9-13(-15) cm x 1-1.2mm bright lustrous green, bundled in threes and with a short basal sheath.
Pollen cones are crowded near the proximal end of a new shoot. They are subtended by broad, scarious bracts, spreading, ovoid-oblong to cylindrical, 15 – 20 x 5 – 6 mm, yellowish, turning yellowish brown.
The seed cones are (6-)8 – 13(-15) x (4-)5 – 7 cm when open (width 3.5 – 5 cm when closed)
, light-brown when ripe, long, closed, and curved. They have an irregular conical shape. They are found in clusters of 5 – 10 on the branches. In its native environment Pinus greggii begins flower and cone production at approximately 4 to 5 years of age. The cones ripen in December and January, approximately 21 months after pollination.
The apophysis has a marked transverse keel and a blunt umbo.
Pinus greggii is closely related to and has been crossed successfully with Pinus patula. The main morphological difference with the latter species is found in the needles: those of P. patula are longer and drooping. The bark is also different.
, only in a limited area in the states of Coahuila, Nuevo Leon and Hidalgo.
It occurs somewhat farther north than its close relative, Pinus patula, both ranges overlap slightly. About natural hybridization different opinions exist among specialists. Dvorak says that natural hybrids exist and that artificial hybrids have been successfully made. Farjon says that natural hybrids have not been reported.
Dvorak states that Pinus greggii occurs in two distinct geographic regions in Mexico: a northern population in the States of Coahuila and Nuevo Leon (24° to 25° N latitude) , and a southern population in the States of Puebla, San Luis Potosi, Hidalgo, Queretaro, and Veracruz (20° to 21° N). There is a gap of 360 km between these two populations. There are differences in needle and cone morphology and seed size between the two populations. There are also differences in ecology and size of trees.
It has little resistance to frost conditions, but may endure a sporadic light frost where it occurs at its altitudinal limits. Usually the climate is rather humid in these mountains of northeastern Mexico.
It is nowhere abundant in its scattered range, and always occurred mixed with e.g. Quercus
, Platanus
, Liquidambar, Fraxinus
, and other pines, like Pinus patula
, P. pseudostrobus
, P. teocote
, P. montezumae
, and P. arizonica
var. stormiae; with P. cembroides
and Juniperus flaccida
on dry sites; and at higher and more mesic
locations with Abies vejarii
, Pseudotsuga menziesii
or Cupressus lusitanica
.
Pinus greggii is also introduced in Italy, India, Nepal and Argentina.
Pine
Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
tree native to eastern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, found in two distinct regions. It has an open crown and long and slender branches. The needles are in bundles of three with an average length of 11 cm. The cones are clustered in groups of 5 – 10. The branches en upper trunk is smooth. Pinus greggii is introduced in several countries.
Taxonomy
The species was described by George EngelmannGeorge Engelmann
George Engelmann, also known as Georg Engelmann, was a German-American botanist. He was instrumental in describing the flora of the west of North America, then very poorly-known; he was particularly active in the Rocky Mountains and northern Mexico.-Origins:George Engelmann was born in Frankfurt...
in 1868
Two varieties are found in literature:
- Pinus greggii Engelm. ex Parl. var. australis Donahue & Lopez
- Pinus greggii Engelm. ex Parl. var. greggii
The species name greggii honors Josiah Gregg
Josiah Gregg
Josiah Gregg was a merchant, explorer, naturalist, and author of the American Southwest and Northern Mexico regions. He is most famous for his book Commerce of the Prairies.-Early years:...
(1806 – 1850), a merchant, explorer, naturalist, and author of the American Southwest and Northern Mexico.
Description
Pinus greggiii is a small to medium high tree, reaching a height of 15 – 20 meters.The bark
Bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
remains smooth for a long time in this species, and only old trees have rough bark at the base of the trunk. The bark is thick, with deep, longitudinal fissures and rough, elongated plates. On the upper part of the trunk and branches smooth to finally scaly. Greyish brown.
The crown
Crown (botany)
The crown of a plant refers to the totality of the plant's aboveground parts, including stems, leaves, and reproductive structures. A plant canopy consists of one or more plant crowns growing in a given area....
is loose and open.The branch
Branch
A branch or tree branch is a woody structural member connected to but not part of the central trunk of a tree...
es are long and slender, swaying in the wind, spreading or curved downward, not pendulous, forming a rounded, dense or more open crown. The young twigs are bluish-green.
The winter buds are narrow and sharp pointed, without resin and with loose scales, usually light-brown.
The needles are (7-)9-13(-15) cm x 1-1.2mm bright lustrous green, bundled in threes and with a short basal sheath.
Pollen cones are crowded near the proximal end of a new shoot. They are subtended by broad, scarious bracts, spreading, ovoid-oblong to cylindrical, 15 – 20 x 5 – 6 mm, yellowish, turning yellowish brown.
The seed cones are (6-)8 – 13(-15) x (4-)5 – 7 cm when open (width 3.5 – 5 cm when closed)
, light-brown when ripe, long, closed, and curved. They have an irregular conical shape. They are found in clusters of 5 – 10 on the branches. In its native environment Pinus greggii begins flower and cone production at approximately 4 to 5 years of age. The cones ripen in December and January, approximately 21 months after pollination.
The apophysis has a marked transverse keel and a blunt umbo.
Pinus greggii is closely related to and has been crossed successfully with Pinus patula. The main morphological difference with the latter species is found in the needles: those of P. patula are longer and drooping. The bark is also different.
Distribution
Pinus greggii is found in Mexico in the Sierra Madre OrientalSierra Madre Oriental
The Sierra Madre Oriental is a mountain range in northeastern Mexico.-Setting:Spanning the Sierra Madre Oriental runs from Coahuila south through Nuevo León, southwest Tamaulipas, San Luis Potosí, Querétaro, and Hidalgo to northern Puebla, where it joins with the east-west running Eje Volcánico...
, only in a limited area in the states of Coahuila, Nuevo Leon and Hidalgo.
It occurs somewhat farther north than its close relative, Pinus patula, both ranges overlap slightly. About natural hybridization different opinions exist among specialists. Dvorak says that natural hybrids exist and that artificial hybrids have been successfully made. Farjon says that natural hybrids have not been reported.
Dvorak states that Pinus greggii occurs in two distinct geographic regions in Mexico: a northern population in the States of Coahuila and Nuevo Leon (24° to 25° N latitude) , and a southern population in the States of Puebla, San Luis Potosi, Hidalgo, Queretaro, and Veracruz (20° to 21° N). There is a gap of 360 km between these two populations. There are differences in needle and cone morphology and seed size between the two populations. There are also differences in ecology and size of trees.
Ecology
In its natural habitat Pinus greggiii grows in the cool highlands, at altitudes between 1300 – 2600 m; in the northern part of its distribution at 2300 – 2700m. Annual precipitation is 600 – 800 mm in much of its range, except on the east escarpment of the mountain ranges along the Hidalgo-Veracruz borderline, where it is 1000 – 1600 mm. In the north it is more often found on slightly alkaline soils (pH 7 – 8); in the south on acid soils (pH 4 – 5).It has little resistance to frost conditions, but may endure a sporadic light frost where it occurs at its altitudinal limits. Usually the climate is rather humid in these mountains of northeastern Mexico.
It is nowhere abundant in its scattered range, and always occurred mixed with e.g. Quercus
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
, Platanus
Platanus
Platanus is a small genus of trees native to the Northern Hemisphere. They are the sole living members of the family Platanaceae....
, Liquidambar, Fraxinus
Ash tree
Fraxinus is a genus flowering plants in the olive and lilac family, Oleaceae. It contains 45-65 species of usually medium to large trees, mostly deciduous though a few subtropical species are evergreen. The tree's common English name, ash, goes back to the Old English æsc, while the generic name...
, and other pines, like Pinus patula
Pinus patula
Patula pine, pino patula, pinus patula is a tree native to the highlands of Mexico. It grows from 24° to 18° North latitude and 1800 to 2700 m above sea level. 30 m tall...
, P. pseudostrobus
Pinus pseudostrobus
Smooth-bark Mexican Pine , distinctive names in Spanish, tree endemic to Mexico.It is 8 to 25 m tall, dense and round top, the bark is brown and fissured and smooth when young. It grows between 1300-3250 m. From 26° to 15° north latitude, from Sinaloa, Mexico to Honduras. It occurs within a...
, P. teocote
Pinus teocote
Pinus teocote is a species of conifer in the Pinaceae family.It is found only in Mexico. 20-30 m tall and 75 cm diameter. Straight trunk and dense top. It grows at 1500-3200 mm...
, P. montezumae
Pinus montezumae
Pinus montezumae, known as the Montezuma Pine, is a species of conifer in the Pinaceae family.It is native to Mexico and Central America, where it is known as Ocote. The tree grows about 35 m high and 80 cm in diameter; occasionally it may reach a height of 40 m and diameter of...
, and P. arizonica
Arizona Pine
Pinus arizonica, commonly known as the Arizona pine, is a medium-sized pine in northern Mexico, southeast Arizona, southwest New Mexico, and western Texas in the United States. It is a tree growing to 25-35 m tall, with a trunk diameter of up . The needles are in bundles of 3, 4, or 5, with...
var. stormiae; with P. cembroides
Mexican Pinyon
The Mexican Pinyon ' is a pine in the pinyon pine group, native to western North America.-Distribution:The range extends from westernmost Texas, United States , south through much of Mexico, occurring widely along the Sierra Madre Oriental and Sierra Madre Occidental ranges, and more rarely in the...
and Juniperus flaccida
Juniperus flaccida
Juniperus flaccida is a large shrub or small tree reaching 5-10 m tall. It is native to central and northern Mexico and the extreme southwest of Texas, United States...
on dry sites; and at higher and more mesic
Mesic habitat
In ecology, a mesic habitat is a type of habitat with a moderate or well-balanced supply of moisture, e.g., a mesic forest, a temperate hardwood forest, or dry-mesic prairie. Compared to a dry habitat, a mesic habitat is moister....
locations with Abies vejarii
Abies vejarii
Abies vejarii is a species of fir native to northeastern Mexico, in the states of Coahuila and Nuevo León, where it grows at high altitudes in the Sierra Madre Oriental.It is a medium-sized evergreen tree growing to 35–40 m tall...
, Pseudotsuga menziesii
Coast Douglas-fir
Pseudotsuga menziesii, known as Douglas-fir, Oregon Pine, or Douglas spruce, is an evergreen conifer species native to western North America. Its variety Pseudotsuga menziesii var. menziesii, also known as coast Douglas-fir grows in the coastal regions, from west-central British Columbia, Canada...
or Cupressus lusitanica
Cupressus lusitanica
Cupressus lusitanica, ; Cedro Blanco means White Cedar and is also known as Mexican White Cedar, is a species of cypress native to Mexico and Central America...
.
Cultivation and introductions
Pinus greggii from the southern population was introduced in approximately 10 countries in the subtropics between the 1960s and 1980s. Trials from both northern and southern populations were carried out in Brazil, Colombia, New Zealand, South Africa, and Zimbabwe in the late 1980s. These trials have resulted in plantations on a limited scale (e.g. 1000 ha per year in South Africa).Pinus greggii is also introduced in Italy, India, Nepal and Argentina.
Literature
- Dvorak, W. S. - Pinus greggii. In: Vozzo, J.A. - Tropical Tree Seed Manual. United States Department of Agriculture; Forest Service. 2003. p. 615 – 617. online available as pdf
- Farjon, Aljos – Pines; drawings and descriptions of the genus Pinus. Publ. Brill / Backhuys, Leiden 1984
- Farjon, Aljos & Brian T. Styles – Pinus (Pinaceae). Monograph 75 of Flora Neotropica. New York Botanical Garden, New York 1997
- Farjon, Aljos – World checklist and bibliography of Conifers. 2nd ed. Royal Botanic Gardens, Kew 2001
- den Ouden, P. & Dr. B.K. Boom – Manual of Cultivated Conifers, ed. Martinus Nijhoff, The Hague 1965
- Shaw, George Russell – The genus Pinus. Cambridge 1914. online in gutenberg.org. With beautiful drawing.
- van Wyk, G. - Pinus greggii. In: Pines of Silvicultural Importance - Compiled from the Forestry Compendium, CAB International. Edition: illustrated. Published by CABI, 2002. ISBN 085199539X, ISBN 9780851995397, p. 144f. Online available at Google Books