Juniperus angosturana
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| Juniperus angosturana | ||||||||||||
| RP Adams |
Juniperus Angosturana is a plant from the family of the cypress family (Cupressaceae). It is native to the mountains of eastern Mexico.
description
Juniperus angosturana grows as an evergreen shrub or small tree that can reach heights of 3 to 8 (rarely up to 10) meters and a diameter of up to 50 centimeters at chest height . The trunk often branches out soon. The brown trunk bark comes off in square plates. The thick, twisting branches rise from the trunk to an upright position and form an irregularly shaped crown . The smooth bark of the branches changes color from light brown to gray with age. It peels off in small pieces on young branches and is cracked to mosaic-like on older branches.
The loosely standing outer branches are 4 to 20 millimeters long and 1 to 1.3 millimeters thick. Their foliage with scale-like leaves is limited to the four to five last branches. Both cross-opposed and elongated-diamond-shaped as well as overlapping scale-shaped leaves as well as downward needle-shaped leaves standing in threes in alternate whorls are formed. They are 1 to 1.5 millimeters long and around 0.7 millimeters wide. They are cross-opposite or alternately in threefold whorls on the branches. The upper edges of the needles are finely serrated and hyaline . The visible, sunken glands are rare. They are enlarged to 0.5 to 3 millimeters in the needle-shaped leaves.
Juniperus angosturana is dioeciously segregated ( diocesan ). The numerous, berry-shaped cones are formed with a length of 4 to 6 millimeters and a thickness of 3 to 5 millimeters at the end of very short side branches. Initially, the cones are green in color and, as they ripen, turn purple-blue frosted within a year. When dried out, they are brown in color. Each cone bears one or two light brown seeds. With a length of 3 to 5 millimeters and a width of 2.5 to 4 millimeters, they are egg-shaped to approximately spherical. They are slightly grooved, tapering at the end and have a navel ( hilum ) at the base . The pollen flow takes place from December to January.
Distribution and location
The natural range of Juniperus angosturana is in the Sierra Madre Oriental in Mexico. There the species occurs in the states of Coahuila , Hidalgo , Nuevo León , northeast Querétaro , San Luis Potosí and Tamaulipas .
Juniperus angosturana thrives at altitudes of 1050 to 2800 meters. The species grows in open bushland as well as in forests, on stony slopes and along rivers. It forms mixed stands with Juniperus flaccida , the Mexican pinyon pine ( Pinus cembroides ) and with the Montezuma pine ( Pinus montezumae ).
Systematics
It was first described as Juniperus angosturana in 1994 by Robert Phillip Adams in Biochemical Systematics and Ecology , Volume 22, Number 7, Page 704. A synonym for Juniperus angosturana R.P. Adams is Juniperus monosperma var. Gracilis Martínez .
Hazard and protection
Juniperus angosturana is listed on the IUCN Red List as “not endangered”. It is pointed out, however, that a new check of the risk is necessary. The restriction to the small distribution area can lead to a hazard in the future.
swell
- Christopher J. Earle: Juniperus angosturana. In: The Gymnosperm Database. www.conifers.org, May 22, 2011, accessed on January 22, 2012 .
literature
- Robert P. Adams: Junipers of the World: The genus Juniperus . 2nd Edition. Trafford Publishing Co., Vancouver 2008, ISBN 978-1-4251-6880-3 , pp. 98-99 .
Individual evidence
- ↑ a b c d Christopher J. Earle: Juniperus angosturana. In: The Gymnosperm Database. www.conifers.org, May 22, 2011, accessed on January 22, 2012 .
- ↑ Juniperus angosturana. In: Germplasm Resources Information Network. www.ars-grin.gov, accessed on January 22, 2012 (English).
- ↑ Juniperus angosturana at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed January 22, 2012.
- ↑ Juniperus angosturana in the endangered Red List species the IUCN 2011. Posted by: Conifer Specialist Group, 1998. Accessed January 22, 2012 Design.