Juniperus deppeana
Alligator juniper (Juniperus deppeana )
The alligator juniper (Juniperus deppeana ) is a plant of the genus (Juniperus ) in the family of the cypress family ( Cupressaceae ).
- 3.1 varieties and forms
- 6.1 Literature
- 6.2 Notes and references
- 6.3 External links
Description
Habit
The alligator juniper is reached from 25 to 120 centimeters an evergreen tree or shrub, the plant height of about 10 to 15 (rarely up to 21 ) meters and diameter at breast height. The crown of isolated trees is broad and irregularly conical. They have a relatively short and stout trunk. The shrub grows wide and far spreading. The four -edged branches reach a diameter of about 1 millimeter.
Bark
The name derives from the alligator juniper is the dark reddish - brown to blackish colored bark that resembles the skin of alligators because of their regular rectangular scaling. It is between 2.5 and 10 inches thick. The shed can reach diameter of 2.5 to 5 centimeters. Deeper cortical layers are reddish brown to purple. The thin branches have a pale blue-green bark, which turns light reddish brown to drop the needles.
Wood
The pale yellow, sometimes provided with red stripes heartwood differs in color from the narrow whitish sapwood. The wood is light, soft, densely fibred, durable and brittle. The density is specified depending on the source with 0.453 or 0.58 g / cm ³.
The alligator juniper forms of needle - and scale-like leaves. The indistinctly keeled scales leaves are 1 to 3 millimeters long and have a bluish- green color. They stand in pairs or threes on the branch and overlap. They have a blunt or pointed end and a point-like gland. The lower side keeled needle- shaped leaves are longer than the scale leaves and taper to a sudden. They are found mainly in young trees. They stand in pairs or threes on the branch.
Flowers, cones and seeds
Alligator Junipers are dioecious getrenntgeschlechtig ( dioecious ) and wind-pollinated ( anemophily ). The flowering period extends from January to March. The approximately 3 -millimeter-long male flowers are fleshy and are composed of 10 to 12 scale-like stamens together. The ovules of female cones are located at the egg-shaped and pointed scales. The first blue-gray, 8 to 12 millimeters long, berry -like cones are frosted until the 2nd year in September to December and then ripe red-brown and white. The edible " flesh " is to Mature dry, floury and fragrant. Each pin includes pedunculated 3-5 about 5 millimeters large brown seeds.
The seeds are flattened on one or two sides of something. The thousand-seed weight is about 35.71 grams.
Chromosome number
This Wacholderart has a chromosome number of 2n = 22
Distribution and location
The natural range of the alligator juniper, including its varieties is primarily in the southwest and south-central United States and northern Mexico. It extends from the mountains of central and southern Arizona on the southwestern New Mexico and western Texas southward to the Mexican provinces of Sonora, Chihuahua and Coahuila. Furthermore, this species occurs in isolated areas in central Mexico, in southern Mexico and neighboring Guatemala.
The alligator juniper settled mostly dry limestone soils usually at the treeline at altitudes 1330-2660 meters. He often comes together with the stone pine ( Pinus edulis), the single-blade jaw before (Pinus monophylla ), the ponderosa pine (Pinus ponderosa), different oak species ( Quercus ) and other species of juniper (Juniperus ). In European collections it is rather rare to find.
System
The alligator juniper (Juniperus deppeana Steud. ) Is placed within the genus juniper (Juniperus ) depending on the author in the subgenus or section Sabina. It is divided into different varieties that are referred to in various sources partly as forms and in some cases also as subspecies. Here Robert P. Adams and Andrea E. Schwarzbach is followed by the analysis of DNA sequences describe 2006, four varieties and within the variety Juniperus deppeana var deppeana specify three forms. Synonyms for Juniperus deppeana Steud. are Juniperus mexicana differences et Deppe and Juniperus pachyphloea Torr .. The specific epithet deppeana chosen in honor of the German naturalist Ferdinand Deppe.
Varieties and forms
We distinguish the following varieties:
- Juniperus deppeana Steud. var deppeana, the nominate form, is found in the U.S. states of Arizona, New Mexico and Texas; further in the Mexican states of Sonora, Coahuila, Nuevo León, Tamaulipas, Zacatecas, San Luis Potosi, Aguascalientes, Hidalgo, México, Puebla, Tlaxcala, Veracruz with three forms: Juniperus deppeana Steud. var f deppeana elongata RPAdams is a scattered growing form in the Davis Mountains of Trans - Pecos, Texas region.
- Juniperus deppeana Steud. var f deppeana sperryi ( Correll ) RPAdams is described in other sources as well as a variety Juniperus deppeana var sperryi Correll. This form is known in only three stocks in the Davis Mountains of Trans - Pecos, Texas region and possibly with a find in the Mexican state of Sonora. The form has a furrowed bark that peels off in strips.
- Juniperus deppeana Steud. var f deppeana zacatecensis ( Martínez ) RPAdams is also known as variety Juniperus deppeana Steud. var zacatecensis Martínez described and is found in the Mexican states of Zacatecas, Durango and the neighboring Aguascalientes. This form can be found in woodlands and grasslands on hills with oak, pine, pinyon pine and juniper trees other. The distribution area is limited to altitudes 1980-2470 m.
Use
The wood of the alligator juniper is used as fuel and for the production of fence posts. It can be processed only by mixing with other kinds of wood to paper. The berry cones served various Indian tribes as food.
Threats and conservation measures
The alligator juniper is led by the World Conservation Union IUCN Red List of endangered species and as a whole not threatened ( "Least Concern" ) referred. However, a reassessment of the situation as deemed necessary and also parts of nature, namely, a variety and two forms are listed as endangered. These are the following taxa (IUCN lists all three as varieties ):
- Juniperus deppeana Steud. var robusta Martínez is by IUCN continue as a unit with the split-off from other sources variety Juniperus deppeana Steud. var ranked patoniana ( Martínez ) Zanoni seen and so well together with her in the threat level at risk ( " Vulnerable "). Also for this variety a reassessment is required. As a hazard causes the coppice - use of trees and the conservation of large specimens are given as shade. This leads to an unbalanced component.
- Juniperus deppeana Steud. var f deppeana sperryi ( Corell ) R. P. Adams - this form leads the IUCN as Juniperus deppeana Steud. var sperryi Corell mainly due to the extremely low inventory, the threat of grazing and tree felling as critically endangered ( " Critically Endangered ").
- Juniperus deppeana Steud. var f deppeana zacatecensis ( Martínez ) R. P. ADAMS - this form also viewed the IUCN as a variety Juniperus deppeana Steud. var zacatecensis Martínez and listed as vulnerable ( " Vulnerable "). She is pushed back to areas where trees provide shade. The stock structure is generally poor.