American hop beech
| American hop beech | ||||||||||||
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| Scientific name | ||||||||||||
| Ostrya knowltonii | ||||||||||||
| Coville |
The American hop beech ( Ostrya knowltonii ) is a species of the hop beech genus ( Ostrya ) and grows as a tree up to 9 meters high. The leaf blades are 2.5 to 6.5 inches long. The distribution area is in the southwest of the United States. It is classified as not endangered in the IUCN Red List .
description
Ostrya knowltonii grows as a tree up to 9 meters high with an open, narrowly rounded crown. The bark is brown-gray and breaks into narrow vertical scales or strips. The twigs are sparsely to moderately hairy and often show stalked glands. The leaves have a stalk covered with stalked glands. The leaf blade is ovate to broadly ovate-elliptical or almost round, 2.5 to 6.5 inches long and 1.5 to 5 inches wide. The leaf base is narrowly rounded to heart-shaped or wedge-shaped, the leaf edge is sharp and irregularly double-serrated, the upper end is pointed. The underside of the leaf is hairy, especially along the leaf veins. The male inflorescences are 2 to 3 centimeters long catkins, the female inflorescences are 0.6 to 1 centimeter long catkins, the fruit heads are 2.5 to 4 centimeters long with a diameter of 1.8 to 2.5 centimeters at maturity. The bracts are 1 to 1.8 inches long and 0.5 to 1 inches wide. The species blooms in late spring.
Distribution and ecology
The natural range is in the United States in northern Arizona , in New Mexico , Texas and in southeastern Utah . The species grows along rivers and on rocky ground in canyons at altitudes of 1200 to 2400 meters. In Utah, the species grows in wet canyons and at the base of natural monoliths in canyon land and in shady areas along the Colorado River and Lake Powell . In Arizona, occurrences are found on both edges of the Grand Canyon in wet canyons near the water and in Oak Tree Canyon in Coconino County . In New Mexico there are stocks in the Guadalupe and Sacramento Mountains , in Mexico they are found in the Guadalupe Mountains National Park. Ostrya knowltonii often grows in forests dominated by pine ( Pinus ) and juniper ( Juniperus ), or in typical oak forests. At higher altitudes it is found together with the yellow pine ( Pinus ponderosa ) and the common Douglas fir ( Pseudotsuga menziesii ). In Texas it grows together with the strawberry tree Arbutus xalapensis , Pinus strobiformis , the yellow oak ( Quercus muehlenbergii ) and the maple Acer grandidentatum .
Hazard and protection
In the Red List of the IUCN was Ostrya knowltonii 2014 not endangered ( "Lower Risk / least concern") out. It is a rare species and populations grow in isolated areas. The Arizona and Utah deposits may have been extinct. Fossil finds have shown that the species colonized the entire Grand Canyon during the last Ice Age and disappeared from the lower elevations about 8,000 years ago. Today's stocks can be seen as leftovers from the Ice Age that have been more or less stable since then. There is a lack of data to assess whether stocks are increasing, remaining stable or decreasing overall. However, there is hardly any human influence in the known distribution area, which suggests that the occurrences are stable. Due to the small populations, the greatest danger comes from random events such as forest fires. There are no special protection measures for the species, but it grows in several protected areas.
Systematics and research history
Ostrya knowltonii is a kind from the genus of hornbeam ( Ostrya ) in the family of coryloideae (Coryloideae). It was first described in the Garden and Forest in 1894 , although there are different information about the author. The Flora of North America , the World Checklist of Selected Plant Families and Tropico give Frederick Vernon Coville as author, the plant list and IUCN refer to Charles Sprague Sargent . According to R. Govaerts, Ostrya chisosensis is also part of Ostrys knowltonii .
use
The species is not used commercially. The wood is hard and heavy, and locally it could have been used to make tool handles, for example.
Individual evidence
- ↑ German name after Robert Zander : Zander. Concise dictionary of plant names. Edited by Walter Erhardt , Erich Götz, Nils Bödeker, Siegmund Seybold . 18th edition. Eugen Ulmer, Stuttgart 2008, ISBN 978-3-8001-5408-1 , p. 597.
- ^ A b c John J. Furlow: Ostrya knowltonii In: Flora of North America. Volume 3.
- ↑ a b c d Ostrya knowltonii in the endangered Red List species the IUCN 2014 Posted by: L. Stritch, 2013. Accessed March 15, 2015.
- ↑ a b Rafaël Govaerts (Ed.): Ostrya. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved September 18, 2018.
- ↑ Gnetum gnemon at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed March 13, 2015.
- ↑ Ostrya knowltonii. In: The International Plant Name Index. Retrieved March 15, 2015 .
- ↑ Pinus knowltonii. In: The Plant List. Retrieved March 15, 2015 .
- ↑ Ostrya knowltonii. In: The International Plant Name Index. Retrieved March 15, 2015 .
literature
- Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico . Volume 3: Magnoliophyta: Magnoliidae and Hamamelidae . Oxford University Press, New York / Oxford a. a. 1997, ISBN 0-19-511246-6 (English).
