Ussurian Pear: the Most Cold Hardy of Pear Trees

This pear is hardy to USDA Zone 3!

Like all pears, cherries, apples, and hawthorns, the Ussurian Pear is a member of the Rosaceae or rose family.

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The flowers of the Ussurian pear tree. These were one of the first trees to bloom in the park

The tree, also known as the Harbin pear or Chinese pear, is native to China, Japan, Korea, and the Ussuri river area, which forms a border between Russia and Manchuria. It is the most cold-hardy of the thirty or so pear species and will grow in USDA zone 3.

The seeds for the tree were brought to the United States in 1926 by a professor from South Dakota who gathered them near Harbin China. This date is disputed by the Morton Arboretum, which states their tree was planted in 1922. The pome of this species is said to be small, hard and not particularly delicious although it might improve in flavor after a frost. The amount of sugar the fruit contains varies widely between varieties.

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Early buds on the Ussurian pear tree

Some sources suggest it might be used for jellies. Although this website lumps the Harbin pear in with other Asian pears, it says the fruit may also have a tenderizing agent, making it good for marinades. In a chat group, another respondent suggested it might be worth trying to make a perry from the fruit.

In any case, the trees take up to eight years to produce fruit (pomes) and may live up to 300 years. The fruit is eaten by small mammals and birds. In the landscape the trees are used as a windbreak or as a specimen tree. Like most pears, Ussurian pears contain a compound that has antibacterial properties and may also serve as a flea and tick deterrent. 

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Ussurian pear tree still sporting snow bumpers

The Ussurian pear (Pyrus ussuriensis) in City park was planted in 1993 and had a trunk diameter of 3.5″. To find this tree: if you start at the intersection of Sheldon Drive and City Park and walk from the South East corner in a straight line south and east from the point of the intersection, you would find the tree between the the two playing fields. 

 

 

 

Hong Song, Kimchee, Diabetes, and the Korean Pine.

The Korean pine is an important component of the habitat for the Siberian tiger.

OLYMPUS DIGITAL CAMERAAs the name implies, this is not a tree native to the United States, although it may be grown here for its ornamental value. The American Conifer Society lists this species, Pinus koraiensis, as native to Korea and Japan. Other sources state it is also native to China and parts of Russia. Some of the musical names this pine is known as around the world are Hong Song, Chosen-goyo and Chosen-matsu.

A World Wildlife site links pine nut trees and their destruction as an important component in the decline of the Siberian (Amur) tiger, which may be extinct in North Korea. The seeds are a food source for both wild boar and deer, prey of the tigers. This same site blames the rising world demand for the lumber from this tree for its illegal logging.

The seeds are a food staple in Asia, and possibly one of few cash crops in parts of Russia. The leaves may be used as a dye. Various parts of the tree also have been used for medicinal purposes, including ear aches and weight loss.

Of interest is the possible satiety value of the seeds from this conifer. Researchers have reported the nuts are high in Pinolenic acid, which may act as an appetite suppressant and also help lower lipid levels. Other studies  suggest pine nut oil may have a role in diabetes control. These nuts are also used in Korean cuisine. The nuts, called Jat, are part of a number of dishes, from kimchee to fruit desserts. This website includes links to recipes.

This white pine with its five needles to a bunch, oldest specimen is reported to be at least  629 years old for a tree found in Mongolia. The tallest tree is reported to be just over 157 feet. This tree was found in mountains in the Russia/China/Mongolia area.

A nursery in Canada states its stock is grown from 100 year old Canadian trees, making it sound as if this species could survive in other areas of the world. The site also has a photograph of a standard-sized pine nut compared to a jumbo pistachio. The implication is that this is a fruitful and beneficial tree to grow for your own use. It states the harvesting of the nuts from the cones is an easy but sticky venture. Rhora’s Nut Farm and Nursery reports the trees produce cones starting at about 7 years, with a few producing as early as six. Each cone yields an average of seventy seeds. Korean pines are grown for nut production in many areas of the continent, including Michigan and Ontario.

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The Korean Pine

The Korean Pine, C134, in the City Park Arboretum may be found along Jackson Street, north of the wooden bridge if you are on the sidewalk. If you are driving, it is slightly north of Olive street. A fairly small tree, it undoubtedly was recently planted. The lack of any visible pine cones might help confirm its young age.

 

 

 

 

 

Bees at the Bee-Bee Tree

Hundreds of saplings may grow under a female tree.

The Korean Evodia is another tree with a checkered history in North America. The Latin name for this tree included on the City Park Tree Guide is given as Evodia danielli but it appears Tetradium danielli  is also used. Other names include Bee tree, Bee-bee tree or bebe tree. Other sources include the name Honey tree and One Hundred Thousand Flower tree. The current USDA map shows it naturalized in Pennsylvania and Ohio, yet many other states are reporting it as having escaped.

Although Pennsylvania has this species on its watch list for invasive potential, at this point it is not known how it might damage the environment. A four-acre patch of escaped trees has been reported in Maryland. A short article published in 2017 gives more information about the nature of this tree and its invasive nature, stating that hundreds of saplings grow under a female tree and it has been seen outcompeting other invasive species such as the tree of heaven and Japanese stilt grass.

First brought to the United States in the early nineteen hundreds, this specimen is native to the Koreas, northwest China and other parts of Asia. Why is it given its various monikers?

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A cluster of buds for the Korean evodia or One Hundred Thousand Flower tree.

Although the many small blooms, in clusters that resemble poorly formed cauliflower heads, are rather high up and hard to see, bees swarm these late bloomers. It is the second week in September here in Colorado and the flowers are still blooming. Purportedly female flowers will turn to stunning red seed pods.

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Bees on the flowers of the Korean Evodia

This propensity for late blooming makes the tree popular with both bees and possibly beekeepers. Although many sites mention this as a nectar source, the references I found date to the 1970s with few current citations. One website suggests a substance made from the seeds is used as both a cooking and hair oil!

In the 1990s the US Forest Service lamented this tree was not used more often for ornamental purposes and suggested it would be a good street tree. Similar to the Amur cork tree, parts of Korean evodia have been used in Chinese medicine for 2000 years. It has been used to treat arthritis, headaches, gastric upset, and other ailments. Both WebMD and RxList suggest there is not enough evidence to show if any parts of the plant are effective.WebMD includes a number of drugs with which evodia may interact and cautions pregnant and breastfeeding women from using it. Surgical patients should also use caution as it might interfere with blood clotting.

C185 Korean Evodia (Evodia danielii) is either no longer tagged or the tag is nearly impossible to find when the tree is blooming. At the right time of year, though, it is fairly easy to identify by the many bees buzzing around its flowers and its somewhat unusual  shape. If you found the Amur Cork, walk slightly south and west from there. Although not perfectly aligned with Olive Street, you can also start from where Olive Street tees into Jackson and walk west and slightly south across the park to find it. It is near a large evergreen tree.

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Korean Evodia in August

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Amur Cork—Landscape Lovely or Harmful Invader?

First brought to the United States in 1856

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Amur cork tree

Amur cork  tree (Phellodendron amurenses) is native to China, Korea, and other areas of Asia. It was first brought to the United States in 1856 and grown in the Harvard Botanic gardens as early as 1908. From 1933 it has been reported to have naturalized in New York. Currently it is considered an invasive plant in a number of states. As an invasive plant it crowds out native trees and produces berries which are less nutritious than the nuts of native trees; its berries do not have the same essential fats needed for wildlife to survive through the winter.

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Leaves of the Amur cork tree

Some of the sources referenced above speculate that the trees were brought from Asia by railroad workers. The trees’ growth patterns have contributed to its “success” in crowding out native specie. By suppressing the growth of canopy trees, it has become one of the dominate trees in eastern states. Although many states warn against planting Amur cork, others suggest Phellodendron amurenses is a good landscape variety. A few suggest only male trees be considered. This might be a reasonable solution in areas were there are no others, but in areas where the trees have naturalized, the male tree may still fertilize female trees and add to the problem.

Possibly one of the reasons Amur Corks were originally brought to North America is that it is considered to be one of the fifty most important herbs used in Chinese medicine. Some of its compounds have been used to treat meningitis, arthritis, cancers, and diseases of the lungs. The Ainu population of Japan also used parts of this tree as a painkiller.

WebMD mentions most of the uses above. It also states some of the trees’ compounds, such as berberine, might lower blood sugar and LDL cholesterol. At the same time they include warnings about possible harmful effects. There is limited scientific research to support usage.

Other non-medicinal uses have been mentioned; older literature suggests the bark as a substitute for cork.

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The corky trunk of the Amur Cork Tree

It may be used for cork in Russia. An oil made from seeds may have insecticidal properties. A yellow dye obtained from inner layers of bark, was used to produce yellow-tinted paper, useful in distinguishing the important of various Chinese documents.

The Amur cork tree (C138) may be found in City Park  where Olive Street intersects with Jackson Street. As can be seen in the photo at the beginning of this post, the tree is almost directly across from Olive Street street.