Pinus pinceana
| Pinus pinceana | ||||||||||||
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Pinus pinceana |
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| Gordon & Glend. |
Pinus Pinceana is a plant from the genus of pine trees ( Pinus ) within the family of the Pinaceae (Pinaceae). The natural range is in northeastern Mexico.
description
Appearance
Pinus pinceana grows as an evergreen shrub or small tree that reaches heights of 6 to 10 or rarely up to 12 meters. The trunk reaches a chest height diameter of 20 to 30 centimeters. It is short, often branched, twisted and forked just above the ground. The trunk bark is brown-gray and flakes off in irregular plates in the lower area and on the lowest branches. The branches are ascending or spread out, higher-order branches are long, thin and pliable, the branches drooping and form a broad, irregular, open crown. Young shoots are brown-gray to gray, thin, flexible, smooth and hairless.
Buds and needles
The scale leaves are 3 to 4 millimeters long and light brown. The vegetative buds are ovate-round to ovate-conical, about 4 millimeters long and not resinous.
The needles usually grow in threes, rarely in groups of four in a needle sheath about 10 millimeters long, which soon opens or curls up and falls off. The needles are gray-green, straight, stiff, 5 to 12 sometimes up to 14 centimeters long and 0.8 to 1.2 millimeters wide, with entire margins and pointed. The adaxial sides show two to four, rarely five stomata lines . Two large resin channels are formed. The needles stay on the tree for two to three years.
Cones and seeds
The pollen cones are reddish to yellowish and, with a length of 8 to 10 millimeters and a diameter of 4 to 5 millimeters, ovoid-elongated.
The seed cones grow laterally, not on the outermost branches, individually or rarely in pairs on a 1 to 2 centimeter long, thin, curved and easily breaking stalk. The seed cones are ovate-elongated to short cylindrical with a length of 5 to 10 centimeters, often irregularly shaped and have an open diameter of 3.5 to 6, rarely up to 7 centimeters. The 30 to 60 seed scales usually only open a little. They are easy to move, thickly woody and have one or usually two cup-shaped indentations that contain the seeds. The apophysis is glossy reddish brown and sometimes shows concentric colored rings or radial stripes. It is rhombic to pentagonal in outline, clearly raised, keeled transversely and has an angular or wavy upper edge. The umbo lies dorsally, is about 5 millimeters high, flattened at the tip and reinforced with a small spike .
The seeds are egg-shaped with a length of 11 to 14 millimeters and a diameter of 7 to 8 millimeters. Seed wings are missing as soon as the seeds have detached from the seed scales.
Distribution, locations and endangerment
The natural range of Pinus pinceana is in the northeastern Mexican states of Coahuila , Hidalgo , Querétaro , San Luis Potosí , Nuevo León and Zacatecas . There are three main areas , one in the north in Coahuila, Zacatecas and Nuevo León, one in the south in Hidalgo and Querétaro and one in between in San Luis Potosí. The populations in the northern part are genetically different from the populations in the other parts. Pinus pinceana often grows on calcareous slopes in gorges ( barrancas ) at altitudes of 1400 to 2300 meters in mountains with a dry climate. In Nuevo León there are also stocks at altitudes from 1100 to 1700 meters. The annual rainfall is 300 to 600 millimeters, with the higher values being found in the southern part of the range. Most of the precipitation falls in summer. The distribution area can probably be assigned to winter hardiness zone 8 with mean annual minimum temperatures of −12.2 to −6.7 ° Celsius (10 to 20 ° Fahrenheit ).
Pinus pinceana usually grows widely. They are sometimes found together with Pinus cembroides , more often with Juniperus flaccida , but mostly with hard-leaved vegetation and deciduous shrubs such as species of the genus Prosopis , the mimosa ( Mimosa ), Karwinskia , Leucaena , the pagoda trees ( Sophora ), the oaks ( Quercus ), Cercocarpus , Gochnatia and Fouquieria and with species of the succulent genera of the palm lily ( Yucca ), the agave ( Agave ) and the opuntia ( Opuntia ).
In the Red List of the IUCN is Pinus Pinceana as "not at risk" classified (= "Least Concern"). The distribution area extends over a length of more than 750 kilometers from north to south and an area ( extent of occurence ) of 20,000 square kilometers. Due to the incoherent distribution area and the scattered occurrence, however, stocks are only found on about 2000 square kilometers ( area of occupancy ). Despite a possible threat from the use of the wood as firewood, there is no clear sign of a decline in stocks. Only 8 percent of the stocks are in protected areas, the stocks in Nuevo León are in the Parque Nacional Cumbres de Monterrey .
Systematics
The first description of Pinus pinceana was in 1858 by George Gordon and Robert Glendinning in The Pinetum: being a synopsis of all the coniferous plants at present known ... London. , Page 204. The specific epithet pinceana honors Robert T. Pince (about 1804 to 1871), a gardener from Devon , which refers to fuchsia ( Fuchsia specialized). Apart from the name there is no connection to the species. A synonym for Pinus pinceana Gordon & Glend. is Pinus latisquama Engelm .
The kind Pinus Pinceana belongs to subsection cembroides from the section Parrya in the subgenus strobus within the genus of Pinus .
use
Pinus pinceana is not used economically. The seeds are edible, but the tree specimens are rare, difficult to access and form fewer cones than, for example, Pinus cembroides . It is not cultivated outside of botanical gardens.
swell
literature
- Aljos Farjon: A Handbook of the World's Conifers . tape 2 . Brill, Leiden-Boston 2010, ISBN 978-90-04-17718-5 , pp. 609, 735-736 .
- James E. Eckenwalder: Conifers of the World. The Complete Reference . Timber Press, Portland, OR / London 2009, ISBN 978-0-88192-974-4 , pp. 463-464 .
Individual evidence
- ^ Aljos Farjon: A Handbook of the World's Conifers. Volume 2, p. 735
- ↑ a b James E. Eckenwalder: Conifers of the World , p. 463
- ^ Aljos Farjon: A Handbook of the World's Conifers. Volume 2, pp. 735, 737
- ↑ a b c d e f Aljos Farjon: A Handbook of the World's Conifers. Volume 2, p. 737
- ↑ a b Pinus pinceana in the IUCN Red List of Threatened Species 2019.1. Posted by: S. Favela, P. Thomas, 2012.
- ↑ a b James E. Eckenwalder: Conifers of the World , p. 464
- ↑ Pinus pinceana at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed April 26, 2019.
- ^ Pinus pinceana in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved April 26, 2019.
- ↑ Christopher J. Earle: Pinus pinceana. In: The Gymnosperm Database. www.conifers.org, 2019, accessed April 26, 2019 (English).
- ^ Aljos Farjon: A Handbook of the World's Conifers. Volume 2, p. 609
Web links
- Vascular Plants of the Americas : Pinus pinceana at Tropicos.org. In: 83 . Missouri Botanical Garden, St. Louis