''Pinus greggii'', or Gregg's pine, is a small to medium high

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. ''World Flora Online'' accepts 134 species-rank taxa (119 species and 15 nothospecies) of pines as cu ...

tree native to eastern

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

, 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 Engelmann George Engelmann, also known as Georg Engelmann, (2 February 1809 – 4 February 1884) was a German-American botanist. He was instrumental in describing the flora (plants), flora of the west of North America, then very poorly known to Europeans; ...

in 1868in Candolle, Prodr. 16 (2): 396 (1868); distribution: Mexico, Sierra Madre Oriental – as given in Farjon 2001, p. 179 Two varieties are found in literature: * ''Pinus greggii'' Engelm. ex Parl. var. ''australis'' Donahue & Lopezin Sida 18 (4): 1092 (1999); distr: Mexico, San Luis Potosi, Querétaro, Hidalgo, Puebla – as given in Farjon 2001, p. 179 * ''Pinus greggii'' Engelm. ex Parl. var. ''greggii''distr: Mexico, Coahuila, Nuevo León – given with no further ref. in Farjon 2001, p. 179 The species name ''greggii'' honors

Josiah Gregg Josiah Gregg (19 July 1806 – 25 February 1850) was an American merchant, explorer, naturalist, and author of '' Commerce of the Prairies'', about the American Southwest and parts of northern Mexico. He collected many previously undescribed pla ...

(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.Farjon 1984, p. 83 says: small tree 15m.; Farjon&Styles 1997, p. 193 say: small to medium (height to 20 – 25m) The

bark Bark may refer to: Common meanings * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Arts and entertainment * ''Bark'' (Jefferson Airplane album), ...

remains smooth for a long time in this species, and only old trees have rough bark at the base of the trunk.Farjon 1984, p. 83 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.Farjon&Styles 1997, p. 193 The

crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, parti ...

is loose and open. The

branch A branch, also called a ramus in botany, is a stem that grows off from another stem, or when structures like veins in leaves are divided into smaller veins. History and etymology In Old English, there are numerous words for branch, includ ...

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.Farjon 1984, p. 83; Farjon&Styles 1997, p. 193 say: reddish brown to grey-brown 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,Farjon&Styles 1997, p. 193; Farjon 1984, p. 83 says: 8 – 15 cm long, yellowish-green and thin 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),Farjon&Styles 1997, p. 193; Farjon 1984, p. 83 says: 8 – 15 cm long 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.Dvorak 2003, p. 616 The apophysis has a marked transverse keel and a blunt umbo. Pinus greggii 02

''Pinus greggii'' is closely related to and has been crossed successfully with ''

Pinus patula ''Pinus patula'', commonly known as patula pine, spreading-leaved pine, or Mexican weeping pine, and in Spanish as ''pino patula'' or ''pino llorón'', (''patula'' Latin = "spreading") is a tree native to the highlands of Mexico. It grows from ...

''. 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.Shaw 1914, p. 86

Distribution

''Pinus greggii'' is found in Mexico in the

Sierra Madre Oriental The Sierra Madre Oriental () is a mountain range in northeastern Mexico. The Sierra Madre Oriental is part of the American Cordillera, a chain of mountain ranges (cordillera) that consists of an almost continuous sequence of mountain ranges that ...

, only in a limited area in the states of Coahuila, Nuevo León 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.Dvorak 2003, p. 615 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 León (24° to 25° N latitude), and a southern population in the States of Puebla, San Luis Potosí, Hidalgo, Querétaro, 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.Farjon&Styles 1997, p. 193; Farjon 1984, p. 83 says: between 1500 and 2700 m 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 An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...

'', ''

Platanus ''Platanus'' ( ) is a genus consisting of a small number of tree species native to the Northern Hemisphere. They are the sole living members of the family Platanaceae. All mature members of ''Platanus'' are tall, reaching in height. The type ...

'', ''

Liquidambar ''Liquidambar'', commonly called sweetgum (star gum in the UK), gum, redgum, satin-walnut, styrax or American storax, is the only genus in the flowering plant family Altingiaceae and has 15 species. They were formerly often treated as a part of ...

'', ''

Fraxinus ''Fraxinus'' (), commonly called ash, is a genus of plants in the olive and lilac family, Oleaceae, and comprises 45–65 species of usually medium-to-large trees, most of which are deciduous trees, although some Subtropics, subtropical specie ...

'', and other pines, like ''

'', '' P. pseudostrobus'', '' P. teocote'', '' P. montezumae'', and '' P. arizonica'' var. ''stormiae''; with '' P. cembroides'' and ''

Juniperus flaccida ''Juniperus flaccida'' (drooping juniper, weeping juniper or Mexican juniper; Native American names include ''tláscal'') is a large shrub or small tree reaching (rarely to 15 m) tall. It is native to central and northern Mexico (from Oaxaca no ...

'' on dry sites; and at higher and more mesic locations with ''

Abies vejarii ''Abies vejarii'' is a species of fir native to northeastern Mexico, in the states of Coahuila, Nuevo León, and Tamaulipas, where it grows at high altitudes (2,000–3,300 m) in the Sierra Madre Oriental.Farjon, A. (1990). ''Pinaceae. Drawings a ...

'', ''

Pseudotsuga menziesii The Douglas fir (''Pseudotsuga menziesii'') is an evergreen conifer species in the pine family, Pinaceae. It is the tallest tree in the Pinaceae family. It is native plant, native to western North America and is also known as Douglas-fir, Dougl ...

'' or ''

Cupressus lusitanica ''Hesperocyparis lusitanica'', the Mexican cypress, cedar-of-Goa or Goa cedar, is a species of Cupressaceae, cypress native to Mexico and Central America (Guatemala, El Salvador and Honduras). It has also been introduced to Belize, Costa Rica a ...

''.

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.van Wyk 2002, p. 144den Ouden & Boom 1965 do not have information on ''Pinus greggii''

References

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

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. , , p. 144f. Online available a
Google Books

External links

at conifers.org {{Taxonbar, from=Q137015 Trees of Northern America Trees of temperate climates Drought-tolerant trees greggii Near threatened plants Flora of the Sierra Madre Oriental