Crataegus douglasii

Oregon hawthorn (Crataegus douglasii ), illustration

The Oregon hawthorn (Crataegus douglasii ), and Douglas hawthorn (English: Douglas hawthorn, black hawthorn, river hawthorn, western thornapple ) called, is a species of the genus hawthorn (Crataegus ) in the rose family ( Rosaceae ). It is found in northern and western North America. His German trivial name from the Oregon hawthorn the U.S. state of Oregon.

• 5.1 Notes and references

Description

Appearance and leaf

The Oregon hawthorn grows as a compact, upright shrub or small tree, reaching heights of growth of mostly 1-4, rarely up to 6 meters. There are offshoots formed and so stocks are on vegetative way formed. The stems are straight and stocky and with 1 to 2.5 centimeters long spines reinforced. The gray to brown bark is smooth or sometimes scaly. The thin branches have a bright red, bare bark.

The alternate arranged on the branches leaves are petiolate 3 to 6 inches long. The simple leaf blade is about as long as wide, obovate with 3-6 inches and tapers towards the petiole. The leaf margin is weakly lobed and toothed. Both leaf surfaces are pubescent to glabrous.

Inflorescence and flower

In each case, some flowers are borne in a lateral or terminal inflorescence. The hermaphrodite flowers are fünfzählig and radial symmetry with a double perianth. The five sepals are fused bell-shaped. The five calyx teeth are triangular, entire and recurved. The five free, white petals are circular with a length of 5 to 7 mm. The free, depending on the variety, ten or twenty stamens have pink dust bag. There are usually three to five pens available.

Fruit and seeds

The Oregon hawthorn wearing dark red to blackish, bare apple fruit which have a diameter of about 1 centimeter. An Oregon hawthorn tree bears fruit 550 on average. The fruits are fully ripe in Oregon in the second half of August and in Washington in the second half of July. There shall be many viable seeds.

Synecology and autecology

Many moss and lichen species colonize the bark.

Many species of birds build their nests and breed in Oregon Hawthorn. Small mammals live in the hedges.

The Oregon hawthorn grows mostly at altitudes 670-1645 m. He thrives in a variety of environments, from forest to scrubland.

Use

The fruits of the Oregon hawthorn were some Indian tribes such as the Cheyenne to food.

System

The first description of Crataegus douglasii was in 1836 by John Lindley in Edwards 's Botanical Register, 21, table 1810. Crataegus douglasii Lindl A synonym for. Crataegus punctata var is brevispina Douglas ex Hook .. The specific epithet honors the Scottish botanist David douglasii Douglas ( 1799-1834 ).

There are three varieties of Crataegus douglasii, which differ in flower characteristics and distribution:

• Crataegus douglasii Lindl. douglasii var: She has ten stamens. It is native to the northern Rocky Mountains.
• Crataegus douglasii var rivularis ( Nutt. ) coffin. Whether the rank of a species Crataegus rivularis Nutt. has discussed She has ten stamens. It is native to the northern Rocky Mountains.
• Crataegus douglasii var suksdorfii coffin. Whether she has the rank of a species Crataegus suksdorfii ( Sarg. ) Kruschke is discussed. She has twenty stamens. It is located on the west side of the Cascade Mountains.

Swell

• Crataegus douglasii. In: WTU Herbarium Image Collection. Burke Museum, University of Washington, accessed on 24 August 2011 ( english ). ( Description section )
• RJ Habeck, 1991 Data Sheet - Crataegus douglasii in FEIS = Fire Effects Information System of USDA = United States Department of Agriculture. (Section Description and systematics)