Japanese Knotweed

Japanese Knotweed, Polygonum cuspidatitm, is right up there with Oriental Bittersweet in its ability to take over the landscape. It seems to like moist ground as I most often find it bordering swamp and pond.

Yet in spite of its invasiveness, Japanese Knotweed shows many uses. From Wikipedia:

Japanese knotweed flowers are valued by some beekeepers as an important source of nectar for honeybees, at a time of year when little else is flowering. Japanese knotweed yields a monofloral honey, usually called bamboo honey by northeastern U.S. beekeepers, like a mild-flavored version of buckwheat honey (a related plant also in the Polygonaceae).

The young stems are edible as a spring vegetable, with a flavor similar to mild rhubarb. In some locations, semi-cultivating Japanese knotweed for food has been used as a means of controlling knotweed populations that invade sensitive wetland areas and drive out the native vegetation. Some caution should be exercised when consuming this plant because it contains oxalic acid, which may aggravate conditions such as rheumatism, arthritis, gout, kidney stones or hyperacidity.

Both Japanese knotweed and giant knotweed are important concentrated sources of resveratrol, replacing grape byproducts. Many large supplement sources of resveratrol now use Japanese knotweed and use its scientific name in the supplement labels. The plant is useful because of its year-round growth and robustness in different climates.

Japanese knotweed is a concentrated source of emodin, used as a nutritional supplement to regulate bowel motility. The roots of Japanese knotweed are used in traditional Chinese and Japanese herbal medicines as a natural laxative. The active principle responsible for the laxative effect is emodin, present in its natural form as a complex of its analogs. Emodin has a mild laxative effect in doses of 20 to 50 mg per day.

From Annual Report of The Pennsylvania State College:

The Japanese Knotweed, also known as the Giant Knotweed, is a newcomer into the weed society. In the first edition of Britton and Brown's "Illustrated Flora of the United States and Canada" this plant was reported as having escaped locally in the vicinity of Philadelphia, Pennsylvania, Schenectady, New York, and Atlantic Highlands, New Jersey; in the second edition of the same work, published in 1913, the plant is described as having escaped from cultivation locally throughout the entire range from Newfoundland to the parallel of the southern boundary of Virginia and from the Atlantic Ocean westward to the 102nd meridian. As the name implies, the plant was introduced from Japan.

At present the Japanese Knotweed is offered for sale in the catalogs of practically all the leading seed houses. In several places in the vicinity of the College, the plant has escaped its bounds to become a vile weed difficult of control; the heavy, woody, deepseated root stock makes this plant extremely pernicious once it leaves the desired bounds. For this reason intending purchasers are warned against the introduction of the plant into their garden. Similar complaint has been registered against the plant by Mr. John Ellis while acting in the capacity of gardener in the Brooklyn Botanic Garden.

Annual Report of The Pennsylvania State College. Harrisburg, 1919. 325. Web. Google Book Search. 1 Nov 2009.

"Japanese knotweed." Wikipedia, The Free Encyclopedia. 30 Oct 2009, 11:36 UTC. 2 Nov 2009 <http://en.wikipedia.org/w/index.php?title=Japanese_knotweed&oldid=322903449>.

Burning Bush

In yesterday's post I mentioned Euonymus alata, Burning Bush, a species that grows in my yard. Here it is! Alas, it's within the Massachusetts noxious list. I am harboring a criminal! :-)

From Addisonia:

"This, one of the best of all our decorative shrubs, grows native in Japan, Manchuria, the Amur region, and in north and central China. It is one of the shrubs easy to grow, accommodating itself readily to its surroundings, and is a thing of beauty in summer and winter. Its crisp fresh foliage gives it a dainty appearance in the month of May, when its flowers usually appear. As the season advances the leaves become of a grayer hue, and in the autumn turn to a rich crimson, which, with the bright orange-red of the exposed arils, makes it one of the most conspicuous shrubs of that season. As the leaves fall the bright red fruit appears even more conspicuous, and the corky wings, of a brown color, become more evident, adding a curious as well as attractive touch not seen in other shrubs. It may be readily propagated from seeds."















The New York Botanical Garder. Addisonia: Colored Illustrations and Popular Descriptions of Plants Volume 3. Lancaster, PA 1918. 7-8. Web. Google Book Search. 29 Oct 2009.

Oriental Bittersweet

At this time of year, the profusion of Oriental Bittersweet becomes readily apparent when huge blankets of yellowing leaves hang from roadside trees. Pretty as it is, Celastrus orbiculatus can certainly overtake the landscape. As it climbs into trees, it smothers with its shading and can topple trees with excess weight and surface exposure during high winds or heavy snows.

Here are bittersweet vines girdling a Black Walnut. In contrast, the lovely lichens live peacefully, neither taking from nor giving to their support.

Birds feeding on the berries spread seed and frustrate control.

Multiflora Rose

Multiflora Rose is another alien invasive species. Still, it's quite a beauty in flower and fruit.

I find the issue of invasiveness interesting. Upon digging, I came across some information here. See the "Annotated Species Lists" and "Publications" for details. And, see this for the nitty-gritty on invasiveness in Massachusetts. Here's some of my weekend's reading!

Also, be sure to check out Gretchen's comments from yesterday on this species.


From Wikipedia:

"In eastern North America, Multiflora Rose is now generally considered an invasive species, though it was originally introduced from Asia as a soil conservation measure, as a natural hedge to border grazing land, and to attract wildlife. It is readily distinguished from American native roses by its large inflorescences, which bear multiple flowers and hips, often more than a dozen, while the American species bear only one or a few on a branch.

"Some places classify Multiflora rose as a "noxious weed". In grazing areas, this rose is generally considered to be a serious pest, though it is considered excellent fodder for goats."


From The Magazine of Horticulture, Botany, and All Useful Discoveries and Improvements in Rural Life:

"The Tennessee or Prairie Rose. In our March number, (p. 98,) we gave an article by Mr. Pierce, on the Prairie rose. It has since been copied into the western papers, and in the Ohio Ktatesm-an with some preparatory remarks, which may be interesting to lovers of this beautiful class.

"The writer states that our correspondent Mr. Pierce, was mistaken in saying that this rose has produced no double variety. " Twenty-two years since, Mrs. Montjoy found a double multiflora rose growing wild, on an island in the Licking River, Ky., a few miles south of Cincinnati. It had all the peculiarities of the single variety, except that the petals were as numerous, and were formed similar to the Chinese multiflora, the rose being about three times as large. This rose was brought by Mr. Buchanan to this city fifteen years ago. He obtained the cuttings from the garden of Gen. Taylor, of Newport, Ky. Mr. B. gave some to Mr. Schnetz, who raised many of them, since which it has been widely disseminated. It is known here by the name of the ' Montjoy Rose,' or ' double native multiflora,' and it deserves to be a great favorite.

"Another variety' of our wild multiflora rose was found in the Scioto Valley, near Chillicothe, by Mrs. Gov. Worthington ; this was semi-double.

"Another beautiful variety was found near Urbana, O., by Mr. John H. James. This was single, but with spotted petals."

"Rosa multiflora." Wikipedia, The Free Encyclopedia. 30 Sep 2009, 08:17 UTC. 30 Sep 2009 <http://en.wikipedia.org/w/index.php?title=Rosa_multiflora&oldid=317052296>.

Hovey, C. M. ed. The Magazine of Horticulture, Botany, and All Useful Discoveries and Improvements in Rural Life. Vol. X. Boston, 1844. 174. Web. Google Book Search. 1 Oct 2009.

Japanese Barberry

Japanese Barberry debuted in April (Can you believe we're in October?) while in flower. Here's a different specimen with fruit. This alien bush makes it into the Massachusetts noxious weed list.


This 1920 excerpt from The American City has a differing viewpoint on the issue of invasiveness:

"It is by making use of the occasional horticultural happening, or by deliberate breeding, that our wealth of trees and plants, useful either for their fruit or their beauty, is increased. Japan has added materially to the hardy trees and plants in general use throughout our country. Perhaps one of the most universally useful shrubs from that country is the Japanese barberry (Berberis Thumbergi). It is not only graceful and beautiful, but free from insect troubles, extremely hardy, and disposed to thrive under a great variety of soils and climatic conditions. When in doubt as to what to plant, one can safely plant Japanese barberry."


The Garden Magazine not only echoes the above advice but also clears up misunderstandings that arose over fears of wheat rust:

"The most generally desirable low hedge plant that can be grown in the Northern states is probably the Japanese Barberry. The Common Barberry and the Purple-leafed Barberry might as well be eliminated now as later. The use of these two plants is being decried and even prohibited in many Western states because of their tendency to spread the wheat rust. This fault is not shared by the Japanese B. Thunbergii, although many a hedge of this fine plant has been sacrificed by ill-informed gardeners who did not realize that the Japanese Barberry was not the undesirable citizens."


Grant, Arthur Hastings; Buttenheim, Harold Sinley. The American City. Volume XXIII. New York, October 1920. 459. Web. Google Book Search. 30 Sep 2009.

Farrington, E. I. The Garden Magazine: Revising Our List of Hardy Shrubs. New York, 1919. 222. Web. Google Book Search. 30 Sep 2009.

Autumn Elaeagnus

Sometimes an ID is just so darned exciting! This one's been in the works for weeks and I had finally decided upon Pin Cherry. Then last night, still feeling unsure, I went back to my trusty The Shrub Identification Book and worked through the basics--the absence of leaf serrations, back side leaf coloration, fruit size and color.

Now I can say with some confidence that here we have the Autumn Elaeagnus, Elaeagnus umbellata, also known as Autumn Olive. Alas, the alien species, native to China and Korea, is listed as a prohibited noxious weed species in Massachusetts. Here's the state's full noxious weed list.

So be it. I still consider it a beautiful shrub and I enjoyed photographing it on many recent occasions.