Quercus engelmannii
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Quercus engelmannii ( English Engelmann oak, Pasadena oak ), is a species of the beech family. It isnative tosouthern California and the northwest of the Mexican state of Baja California . The species is classified as endangeredby the IUCN .
description
Quercus engelmannii is a small tree up to 10 meters high with an elliptical crown. Usually the species is evergreen , but can also shed its foliage in summer due to drought. The bark is thick, furrowed and light gray-brown. The leaves are leathery, 3… 6 cm long and 1… 2 cm wide, blue-green in color and flat or wavy and with entire margins. The flowers are catkins ; the fruit is a 1.5 ... 2.5 centimeter long acorn that ripens within 6 ... 8 months after pollination.
The wood is dark brown and firm, but has a tendency to warp and crack as it dries, making it unsuitable for construction.
distribution
The species is from the foothills of the San Gabriel Mountains in eastern Los Angeles County to the Santa Ana Mountains in Orange County and the western foothills and mesas of the Peninsular Ranges in Riverside and San Diego Counties to the Sierra de Juarez and Sierra San Pedro Mártir common in northern Baja California. They are usually found in savannahs and forest areas above the arid coastal plain, but not higher than 1,300 meters above sea level, where cold winters prevent their occurrence. Quercus engelmannii has a smaller range than most Californian oaks, and urban sprawl in the San Gabriel Valley has already led to its disappearance in most of the northern range. The largest remaining stocks of oak are on the Santa Rosa Plateau in the Santa Ana Mountains near Murrieta in Riverside County and on Black Mountain in San Diego County mahe Ramona .
Fossil evidence shows that Q. engelmannii once had a further distribution area, which extended through today's Mojave Desert and the Sonoran Desert to eastern California and Arizona . Q. engelmannii is most closely related to the Arizona oak (Q. arizonica) and Quercus oblongifolia , which are native to the subtropical Madrean Pine-Oak Woodlands of Arizona and northern Mexico. Q. engelmannii is believed to be the northernmost species of subtropical oak, isolated from its closest relatives by the drought in the deserts of the southwestern United States.
Systematics
Quercus engelmannii belongs to the Quercus ("white oak") section.
Individual evidence
- ↑ Quercus engelmannii Greene . In: The Calflora Database: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals, including the Consortium of California Herbaria . 2019. Retrieved May 27, 2019.
- ^ John M. Tucker: = Quercus engelmannii . In: Jepson Manual . Retrieved May 27, 2019.
- ^ A b E. Beckman: Quercus engelmannii . In: The IUCN Red List of Threatened Species 2017: e.T34020A2840625 . 2017. Retrieved October 25, 2017.
- ↑ Kevin C. Nixon: Quercus engelmannii Greene, Ill. W. Amer. Oaks. 1: 33, plate 17, 1889. . In: Flora of North America @ eFloras.org . Retrieved May 27, 2019.
Web links
- Catalog of Life: Quercus engelmannii
- Quercus engelmannii in the CalPhotos database at the University of California , Berkeley