Nuttall's flower dogwood
| Nuttall's flower dogwood | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Inflorescence of Nuttall's flower dogwood ( Cornus nuttallii ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Cornus nuttallii | ||||||||||||
| Audubon ex Torr. & A.Gray |
The Cornus nuttallii is a plant from the genus of dogwood ( Cornus ). It grows in the moist coniferous forests on the Pacific coast of North America . Sometimes called the Pacific Dogwood , it is occasionally grown as an ornamental wood because of its decorative inflorescences .
The botanical name refers to Thomas Nuttall , who collected this species of flora on the Columbia River and passed it on to Audubon , who mentioned it in his book Birds of America .
description
The Nuttall's flowering dogwood is a small, deciduous tree . The largest specimens reach a stature height of up to twenty, sometimes up to thirty meters. It develops a deep root system with a tap root . The crown is extensive with horizontal side branches in light locations, in the shade it is also narrow and irregular. The young twigs are gray, dark and smooth on the bark on older branches, a cracked bark only develops on thicker trunks.
The opposite , oval leaves are dark green on top, the underside is lighter and somewhat gray in color. The leaf veins are, typical of dogwood, curved towards the tip of the leaf. In autumn the leaves turn red before they fall off.
The inflorescence consists of numerous tiny individual flowers that are grouped in a spherical umbel . The bracts surrounding the inflorescence are striking : usually six, white and pointed, up to seven centimeters long. The number varies from four to seven, and the shape is also quite variable, often very narrow to broadly overlapping bracts appear on an inflorescence at the same time, sometimes slightly pink in color. The pointed ends distinguish this inflorescence from the flower dogwood with indented bracts. In addition to the main bloom in late spring , additional inflorescences often appear again in autumn .
The fruits that form are small, red berries that stand close together. They each contain a core and are eaten by birds and small mammals, which thus ensure the spread ( zoochory ).
The number of chromosomes is 2n = 22.
distribution
The species comes from western North America, from the extreme southwest of Canada to California . In the south of the distribution area higher altitudes are settled than in the north, to the east the distribution is limited by the increasing drought. Only in northern Idaho are there isolated populations further away from the Pacific .
The vegetation in these areas consists mainly of coniferous forests: Typical representatives are the West American hemlock , the Douglas fir , various firs and pines or such giant trees as the coastal redwood . These conifers all grow tall, often over fifty meters, so that Nuttall's flower dogwood grows in the understory or on the edge of the forest. It can still thrive in the shade, but blooms sparsely there. This tree can often be found by streams as it can withstand occasional flooding. The preferred soils are well drained, humus, rich in nutrients, slightly acidic and well supplied with water.
The fungus Discula destructiva , detected in North America since 1976, causes the so-called leaf tan (anthracnose), which leads to the death of the plant. The species has been significantly decimated in its range. Damp locations are particularly affected.
use
Because of the conspicuous bracts and the red autumn color, Nuttall's flower dogwood is cultivated as an ornamental shrub. It places high demands on the soil, needs an even water supply and high humidity. Even under good conditions, it grows very slowly in Central Europe with an annual increase of 15 to 20 centimeters. That is why it is best suited as a solitary shrub in particularly well-kept locations.
Although it can withstand shade, a location that is temporarily sunny is more favorable for abundant flowering. Good soil and air humidity is important in full sun locations.
The varieties 'Ascona', 'Monarch' and 'North Star' with larger and broad bracts are more common on the market, as well as 'Goldspot' with yellowish spotted leaves.
'Eddie's White Wonder' is a hybrid between Cornus florida and C. nuttallii . Hybrids with the Asian flower dogwood ( Cornus kousa ) are also possible and are bred in the USA in order to obtain garden plants that are insensitive to leaf tan (anthracnose).
Individual evidence
- ^ JJ Audubon: Birds of America.
- ↑ American Forest Association (Ed.): National Register of Big Trees ( Memento of the original from July 14, 2007 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ^ Electronic Atlas of the Plants of British Columbia
- ↑ Cornus nuttallii at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
- ↑ CL Watcher: Cornus nuttallii. In: Fire Effects Information System. (On-line). US Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Eds.). 2005.
- ↑ TU Munich: Leaf tan (anthracnose) in the flower dogwood ( Memento from January 3, 2015 in the web archive archive.today )
- ↑ PPP index. Plant buying guide for Europe. Ulmer publishing house
- ↑ J. Hillier, J. Kelly (Ed.): Trees and bushes. Thalacker, 1997, p. 240.
