Utah juniper
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Utah Juniper ( Juniperus osteosperma ) in Canyonlands National Park , Utah |
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| Juniperus osteosperma | ||||||||||||
| ( Torr. ) Little |
The Utah juniper ( Juniperus osteosperma ) is a plant from the family of the cypress family (Cupressaceae). It is native to western North America .
description
Habit and bark
Depending on the location, the Utah juniper occurs as an evergreen shrub or tree . The shrub form reaches heights of growth of a maximum of 3 meters. As a tree, with a chest height diameter of 60 to 75 centimeters, it reaches heights of 6 to 12 meters. The short trunk is often forked, multi-stemmed, rarely single-stemmed and eccentric. The open and round crown consists of upward branches. It is reported from individual specimens that have a narrow, cypress-like growth. Young trees have a taproot , which among other things with the mushrooms fasciculatum carotid body and glomus mosseae a mycorrhiza forms.
The scaly bark of the branches and the bark of old trees is red-brown, but can also be gray to ash-gray due to weathering . The trunk bark peels off in thin, gray-brown stripes, while the bark of the branches is smooth.
Wood
The light yellowish brown heartwood differs in color from the wide white sapwood . The brittle wood is relatively soft and durable. It smells less aromatic than that of other juniper species.
leaves
The bright yellow-green, rhombic to egg-shaped scale leaves of the Utah juniper lie crosswise opposite and less often in whorls of three except for the outermost tips close to the rounded branches. If you rub the rough-feeling leaves, they give off an aromatic smell. Seedlings have 2 to 3 millimeters long, sharply pointed and sub-shaped needles.
Flowers, cones and seeds
The Utah juniper is single-sexed ( monoecious ). The flowering period extends from late March to early April. The rounded and 6 to 12 millimeter thick female cone flowers are terminally on short branches. They are brown to bluish-red in color at flowering time and have 6 pointed, slightly protruding seed scales. Each seed scale has 1 to 2 ovules. The terminal male flowers have 18 to 24 stamens. The seed scales of the female cone flowers become fleshy after pollination and grow into rounded berry cones , usually 8 to 9 millimeters, in extreme values 6 to 13 millimeters in size . The berry cones, which ripen in September of the 2nd year, are firm, gray-bluish, often reddish-brown in color with a gray-bluish coating and have a light wax layer. The dry “pulp” smells strongly aromatic, tastes sweet and is criss-crossed by resin channels. It contains one to rarely two seeds. The hard-shelled seeds are egg-shaped, somewhat angular and have a pointed end with a rounded base. The thousand grain weight is around 91 grams. The diaspores are mainly spread by birds ( ornithochory ).
Distribution and location
The natural range of the Utah Juniper stretches from the mountains in southwest Wyoming and southeast Idaho across the other US states of Utah and Nevada and western Colorado to the eastern slopes of the Sierra Nevada and the Paramint Mountains in California and the plateaus of the northern and central Arizona . Smaller populations can be found in southern Montana and western New Mexico . The main area of distribution is in the Great Basin , where the species is the most common tree species. It is the dominant species of juniper in Utah. In many parts of the semi-deserts of southwest North America, the Utah juniper is the only or dominant tree species.
The Utah juniper is a frost-hardy light tree species of the semi-arid climate with annual rainfall of at least 200 mm. It colonizes slopes with dry and rocky soils at altitudes of 900 to 2,400 meters (RP Adams indicates 1,300 to 2,600 meters). Even in exposed locations, the species survives sandstorms, extreme heat and long dry periods. Together with the pinyon pines, it forms the "Pinyon Juniper vegetation type".
Systematics
The Utah juniper is placed within the genus Juniper ( Juniperus ) to the subgenus Sabina and to the section Pachyphlaeoides . Other authors refer to the sub-genus Sabina as Section Sabina , which has no further taxonomic subdivision. According to RP Adams, he is listed as a member of the group of "junipers with serrated, serrated leaf edges of the western hemisphere". A synonym for Juniperus osteosperma (Torr.) Little is Juniperus utahensis (Engelm.) Lemm. . The specific epithet osteosperma means something like "hard as a bone" and refers to the hard shell of the seeds.
Juniperus osteosperma is said to hybridize with the West American juniper ( Juniperus occidentalis ) in northwestern Nevada .
Diseases and pests
The Utah juniper is not seriously endangered by either insect pests or fungi. Infestation with a subspecies of the semi-parasite Phoradendron juniperinum , which considerably weakens the host plant , is widespread . The fungus Phomopsis juniperovora causes bark necrosis and triggers shoot death. The infestation occurs mainly in tree nurseries. The insect pest Cudonigera houstoneana minimizes the leaves by serving as food for the larvae.
use
The wood is used as fuel and for the manufacture of fence posts. An essential oil can be extracted from the wood , which is used as an odorous substance in cosmetics and as an immersion oil in microscopy. In prehistoric times, ropes, sacks, sandals and mats were made from the bark. The Indians used the wood as roof beams and the berry cones as food. Torches were also made from the bark.
Hazards and protective measures
The Utah juniper is included in the Red List of Threatened Species by the International Union for Conservation of Nature ( IUCN ), but is designated as Least Concern. The reason for this decision is that it is the most common species of the genus juniper in the extensive pine and juniper forest area of the southwestern United States. The Utah juniper also has little commercial value and is common on rocky escarpments and plateaus that are only suitable for a few other plants. The population is increasing and the species is represented in many protected areas.
In the USA this juniper species is protected by the state of Nevada by restricting its use.
literature
- Peter Schütt, Horst Weisgerber, Hans J. Schuck, Ulla Lang, Bernd Stimm, Andreas Roloff: Lexicon of Conifers. Distribution - Description - Ecology - Use; the great encyclopedia . Nikol, Hamburg 2004, ISBN 3-933203-80-5 , p. 219-225 .
- Robert P. Adams: Juniperus of Canada and United States: Taxonomy, Key and Distribution . In: Phytologia . tape 90 , no. 3 , 2008, p. 255-314 ( PDF ).
Individual evidence
- ↑ Juniperus osteosperma in the endangered Red List species the IUCN 2013. Posted by: A. Farjon, 2011. Accessed July 17, 2020th
- ↑ Christmas Trees, Cacti, and Yucca Native to Nevada. (No longer available online.) In: NRCS Natural Resources Concervation Service. Department of Conservation and Natural Resources, archived from the original on March 28, 2010 ; accessed on June 9, 2010 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
Web links
- RPAdams: The Juniperus of the World / Taxa of Juniperus. Retrieved June 9, 2010 (English).
- Juniperus osteosperma. In: The Gymnosperm Database. Christopher J. Earle, accessed June 9, 2010 .
- Plants Database: Plants Profile: Juniperus osteosperma. In: NRCS Natural Resources Concentration Service. USDA United States Department of Agriculture, accessed June 9, 2010 .