Libocedrus chevalieri
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| Libocedrus chevalieri | ||||||||||||
| J.Buchholz |
Libocedrus chevalieri is an evergreen conifer belonging to the common cedar tree ( Libocedrus ). The species makes shrubs or small trees with dense and bushy crowns. The distribution area is in New Caledonia , where it grows near three peaks in bush forest with high annual rainfall. It is threatened with extinction and has no economic importance.
description
Habitus
Libocedrus chevalieri forms spread out shrubs or small trees 2 to 5 meters high with a trunk diameter of about 10 centimeters. The bark is rough and scaly, brown and flakes off in thin, irregular strips and plates. The branches are numerous, ascending, forming a dense, bushy, often rounded crown. The leafy branches grow in the form of fronds that form dense tufts. The outermost branches are almost opposite to alternate, completely covered by leaves, permanent, 20 to 50 millimeters long, about the same length, but shorten towards the end of the main branch. The cross-section is rhombic, somewhat flattened and 3 to 4 millimeters wide.
leaves
The leaves grow opposite to one another and are broad on the main branches. They are overlapping and slightly twofold to the same. Flat and edge leaves are almost the same size, 2.5 to 5 millimeters long and 2 to 2.5 millimeters wide. The surface leaves are triangular-rhombic, pressed, keeled at the tip, pointed and partially covered at the base by the edge leaves flattened on both sides, more or less bent back, pointed to pointed. The leaves form stomata on both sides , in the case of flat leaves near the base, in the case of the edge leaves they are more pronounced and equally frequent on both sides. The leaves are light green, older leaves have a reddish brown tint.
Cones and seeds
The pollen cones stand individually at the branch ends. They are cylindrical, 8 to 10 millimeters long with a diameter of 2.5 to 3.5 millimeters. The 16 to 24 microsporophylls grow cross-opposite. They are shield-shaped, pointed, slightly keeled, with entire margins and have four to sometimes six small, yellow, abaxial pollen sacs. The seed cones are at the ends of branches and develop within a growth period to a length of sometimes only 10, usually 12 to 16 millimeters. The cover scales are slightly wrinkled, the top two are 10 to 14 millimeters long and 5 to 7 millimeters wide, the lower pair is 10 to 12 millimeters long and 3 to 4 millimeters wide. One or two egg-shaped, elongated, slightly flattened, pointed, 5 to 6 millimeters long and about 2.5 millimeters wide, yellowish-brown seeds with two opposite, thin-skinned wings are formed per cones . The smaller wing forms a strip less than 1 millimeter wide, the larger one is yellowish brown, oval-elongated, 8 to 10 millimeters long and 3 to 4 millimeters wide.
Distribution and location requirements
The natural range of Libocedrus chevalieri is in New Caledonia in the southern province on Mt. Humboldt and Mt. Kouakouè, and in the northern province in Poindimiè on Mt. Ton Non. The species grows at heights of 650 to 1620 meters on slopes near the top of the highest peaks in steep terrain in 2 to 5 meters high bush forest. The climate is humid with high annual rainfall.
Danger
In the Red List of the IUCN is Libocedrus chevalieri out as critically endangered ( "Critically Endangered"). The range of the species is limited to isolated populations near three mountain peaks, with the two peaks in the southern province in protected areas. The last collections from the Northern Province date from the 1970s, since then there have been no further finds from this area. The trees show only a slow growth and low regenerative capacity and are endangered by increased fire frequency but also by climate changes. Mining is also permitted in the protected areas, which is another potential hazard. The entire proven distribution area, excluding the uncertain stocks in the Northern Province, covers an area of only 22 square kilometers.
Systematics and research history
Libocedrus chevalieri is a kind of genre the libocedrus ( Libocedrus ) in the family of cypress plants (Cupressaceae). It was first described in 1949 by John Theodore Buchholz in the Bulletin du Muséum National d'Histoire Naturelle . The genus name Libocedrus is derived from the Greek libos for “tear” or “drop”, referring to resin droplets emerging, and from cedrus the genus name of the cedar trees . The specific epithet chevalieri honors the collector L. Chevalier, who worked in New Caledonia in the 1940s and 1950s.
In 2001, Alexander Borissowitsch Doweld assigned the three scaly cedar species from New Caledonia, Libocedrus yateensis , Libocedrus austrocaledonica and Libocedrus chevalieri , to a separate genus, Stegocedrus . This classification is mostly not recognized, however, Stegocedrus chevalieri is only a synonym of the species.
use
The species is not used economically. Some young plants are grown in a few botanical gardens in glass houses for research purposes.
swell
literature
- Aljos Farjon: A Handbook of the World's Conifers . tape 1 . Brill, Leiden-Boston 2010, ISBN 90-04-17718-3 , pp. 506 .
- Helmut Genaust: Etymological dictionary of botanical plant names. 3rd, completely revised and expanded edition. Nikol, Hamburg 2005, ISBN 3-937872-16-7 , p. 340 (reprint from 1996).
Individual evidence
- ↑ a b c d e f g h Aljos Farjon: A Handbook of the World's Conifers , Volume 1, p. 506
- ↑ a b Libocedrus chevalieri in the Red List of Threatened Species of the IUCN 2012. Posted by: P. Thomas, 2010. Retrieved on January 27, 2013.
- ↑ Libocedrus chevalieri. In: Germplasm Resources Information Network (GRIN). United States Department of Agriculture, June 29, 2009, accessed January 27, 2013 .
- ↑ To be precise: Etymological dictionary of botanical plant names. P. 340
- ↑ Stegocedrus. In: The Plant List. Retrieved January 23, 2013 .
Web links
- Christopher J. Earle: Libocedrus chevalieri. In: The Gymnosperm Database. www.conifers.org, November 23, 2012, accessed January 27, 2013 (English).
- Libocedrus chevalieri. In: Faune et Flore de Nouvelle Calédonie. endemia.nc, accessed January 27, 2013 (French, photos and distribution in New Caledonia).
- Libocedrus chevalieri. In: The Plant List. Retrieved January 27, 2013 .