Libocedrus yateensis
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Libocedrus yateensis is a species of conifer from the genus of the common cedar ( Libocedrus ) that forms evergreen shrubs or small trees. The distribution area is in the north and south provinces of New Caledonia . There it grows in river valleys at heights of 150 to 600 meters. It is highly endangered and has no economic significance.
description
Habitus
Libocedrus yateensis forms shrubs or small trees, 2 to 10 sometimes 12 meters high, with trunk diameters of 10 to 30 centimeters. The bark is rough and scaly, reddish brown and flakes off in thin, longitudinal, irregular strips and plates. The branches are ascending or spread out and in young trees they form a conical crown that later becomes bushy. The leafy branches resemble fern fronds and form dense clusters. The outermost branches grow almost opposite to alternate, are completely covered by leaves, remain, of unequal length and shorten towards the end of the main branch. They have a cross section of about 4 millimeters.
leaves
The leaves grow cross-opposite and are bent back or protruding towards the tip, especially on the outer branches. On the outermost branches they are overlapping and clearly two-sided. The face sheets are 1.5 to 2 millimeters long, rhombic, pressed, keeled towards the tip, bespitzt and partially covers the base from the edges of leaves. The edge leaves are flattened on both sides, protruding, sickle-shaped-lanceolate , 2 to 5 millimeters long and 1 to 2 millimeters wide, with entire margins to dry skinned, with a pointed to pointed tip. 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 indistinct on the upper side and on the underside in a clearly visible band reaching to the tip of the leaf. The leaves are shiny olive green, the stomata are bluish white.
Cones and seeds
The pollen cones stand individually at the branch ends. They are cylindrical, 5 to 8 sometimes up to 10 millimeters long with a diameter of 2 to 2.5 millimeters. The 16 to 24 microsporophylls grow cross-opposite. They are shield-shaped, pointed, keeled, with entire margins and have four small, yellow, abaxial pollen sacs. The seed cones are at the ends of branches that form almost identical leaves. They develop within a growing season and become thinly woody. The two upper scales are 8 to 9 millimeters long and 3 to 4 millimeters wide, the lower pair is smaller with lengths of 4 to 6 millimeters and widths of about 2 millimeters. Both pairs are slightly wrinkled and form a 9 to 10 millimeter long cone. One or two egg-shaped, elongated, slightly flattened, 5 to 6 millimeters long and about 2.5 millimeters wide, light 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 is yellowish brown, oval-elongated, 6 to 7 millimeters long and 2.5 to 3 millimeters wide.
Distribution and location requirements
The natural range of Libocedrus yateensis is in New Caledonia in the southern province on the Rivière Bleue-Yaté River and on the Ouinné River and in the northern province near Povila. The species grows at heights of 150 to 600 meters on sediments along fewer rivers than individual trees or in small groups. Neocallitropsis pancheri is the only other representative of the cypress family to be found in this habitat, alongside various shrub and fern species.
Danger
In the Red List of the IUCN is libocedrus yateensis as endangered ( "Endangered") out. The range of the species is limited to 24 square kilometers divided into three isolated populations. Two populations exist in river valleys in the southern province, one of them protected in the Parq Rivière Bleue de Yaté. One population is in the Northern Province near Povila. However, conditions are deteriorating due to forest fires and a lack of regeneration.
Systematics and research history
Libocedrus yateensis is a kind of genre the libocedrus ( Libocedrus ) in the family of cypress plants (Cupressaceae). It was first described in 1949 by André Guillaumin 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 yateensis refers to the place name Yaté , the place where it was first described.
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 . However, this classification is not recognized, Stegocedrus yateensis is only a synonym of the species.
use
The species is not used economically. Some young plants are cultivated 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. 508, 509 .
- 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 Aljos Farjon: A Handbook of the World's Conifers , Volume 1, p. 508
- ↑ a b Libocedrus yateensis in the endangered Red List species the IUCN 2012. Posted by: P. Thomas, 2010. Accessed February 3, 2013.
- ^ Aljos Farjon: A Handbook of the World's Conifers , Volume 1, pp. 508, 509
- ↑ Libocedrus yateensis. In: Germplasm Resources Information Network (GRIN). United States Department of Agriculture, accessed February 3, 2013 .
- ↑ To be precise: Etymological dictionary of botanical plant names. P. 340
- ↑ Stegocedrus. In: The Plant List. Retrieved February 3, 2013 .
- ^ Aljos Farjon: A Handbook of the World's Conifers , Volume 1, p. 509
Web links
- Christopher J. Earle: Libocedrus yateensis. In: The Gymnosperm Database. www.conifers.org, November 23, 2012, accessed on February 3, 2013 .
- Libocedrus yateensis. In: Faune et Flore de Nouvelle Calédonie. endemia.nc, accessed February 3, 2013 (French, photos and distribution in New Caledonia).
- Libocedrus yateensis. In: The Plant List. Retrieved February 3, 2013 .