Tuesday, May 19, 2009

Paulownia tomentosa

I missed the thousandth anniversary of the world's first novel in 2008. Better late than never, I am making amends by observing the thousand and first. The Tale of Genji, which depicts the cloistered world of the imperial Japanese aristocracy of a millennium ago, is thought to have been written in about 1008. An abiding presence in the novel is the empress tree, Paulownia tomentosa. The delicate lavender hue of the Paulownia flower is the color of romantic attachment throughout the tale. That color is murasaki, the first name of Genji's author, Murasaki Shikibu. Genji's adoptive daughter (and concubine!) is also called Murasaki. Genji's mother, who dies shortly after Genji's birth, is the Lady of the Paulownia Court. Genji carries on a romantic affair with his stepmother, who bears an uncanny resemblance to the Lady of the Paulownia Court.

A tree with the aristocratic associations(1) and exquisitely beautiful blooms of Paulownia might be expected to keep only the best company. Sadly, the tree's star has fallen. In Plainfield Paulownias are most likely to be found in the neglected precincts of the railroad tracks, keeping company with disreputable black locusts (http://plainfieldtrees.blogspot.com/2007/05/black-locust-robinia-pseudoacacia.html). You can see the two species commingling in the wooded strip of land that borders the tracks along South Second Street. America doesn't share Japan's enthusiasm for Paulownia. Despite the beauty of its blooms, Paulownia is regarded as a weed in this country.

I'm glad to report that Plainfield has at least a few beautiful and well cared-for Paulownias. One is in the front yard of 1038 Central Avenue, pictured below. I despaired of finding a photogenic Paulownia in town until Hugh Goodspeed directed me to the Central Avenue tree. (If you visit to have a look, don't miss the white oak only yards away, one of the grandest white oaks in the area. It is pictured at the end of this posting.)

Pictured below is another large Paulownia on Leland Avenue in front of Stillman Gardens.

Jo-Ann Bandomer pointed out this tree to me last spring. She sent an email describing it as looking like a tree-form wisteria. A Paulownia in bloom could easily be mistaken for a wisteria. The huge flowers, which appear before the leaves, are of the same general shape and color as wisteria blooms. Once the leaves appear, the resemblance to wisteria is lost. The large, heart-shaped leaves of Paulownias closely resemble the leaves of catalpas (http://plainfieldtrees.blogspot.com/2007/06/catalpa.html).

Paulownia is not often planted in the United States except on tree farms. It's considered messy, prone to splitting, and invasive.(2) We grow the tree on farms to export its wood to Japan. The wood is highly prized in Japan for its light weight, easy workability, and resistance to rot. It is also said to be fire-resistant. Paulownia wood is a traditional material for the fabrication of chests in which to store kimonos. Several sources relate that it was once customary in Japan and China to plant a Paulownia on the birth of a daughter. The tree would grow fast enough to provide wood for a dowry chest at her marriage. The wood is also used for traditional musical instruments and clogs.

The Japanese still value Paulownias for their beauty, not just as sources of wood. The Paulownia tree is honored by depiction of its flower on the seal of the Japanese prime minister. It would be hard to imagine a flower as the symbol of any American government office. What might Dick Cheney's flower have been?

Schooled by samurai movies, Americans think of the Japanese masculine ideal as silent, loyal, duty-bound, fearless, and skilled at swordplay. The Tale of Genji reflects a different pole of Japanese culture. Genji's era preceded the one depicted in samurai films, and the milieu is the court, not the battlefield. The masculine ideal in Genji's world bears little resemblance to the hero of the samurai film. Not hesitant to shed a tear in contemplation of a beautiful view, he seeks to impress the ladies by the skill with which he mixes the colors of his robes and by the cleverness of his poetry. He prides himself on his ability to blend scents for his own personal perfume. He knows nothing of the world outside the hothouse environment of Kyoto and is afraid to leave central Kyoto at night for fear of highwaymen.(3)

I'm on the lookout for another tree to celebrate an anniversary. This year is the 250th anniversary of the birth of Robert Burns. Does anyone know of a photogenic Scotch pine?

White oak 1038 Central Avenue

(1) Not only Japanese royalty, Russian as well. The tree was given its Latin name Paulownia to honor Russian Princess Anna Pavlovna.
(2) Paulownia has earned a place on the Plant Conservation Alliance's Alien Plant Working Group Least Wanted List. http://www.nps.gov/plants/alien/fact/pato1.htm
(3) The World of the Shining Prince, Ivan Morris, Kodansha International 1994, p. 145.
Copyright Gregory Palermo

Thursday, April 9, 2009

New American Chestnuts

Plainfield mayor Sharon Robinson-Briggs will honor the American chestnut at 946 Madison Avenue at the City's Arbor Day celebration Friday April 24.

The tree was planted by Bill Santoriello in 1992 and is now about 10 inches in diameter at breast height. The tree is currently owned by Vicki Blasucci. Lacking a nearby chestnut to pollinate it, the Madison Avenue chestnut has been sterile. But things are looking up for the tree. It will soon have neighbors. The American Chestnut Foundation provided germinated nuts for planting new trees nearby. Bill Santoriello, Vicki Blasucci, and Robin Gates planted four of the nuts this past weekend, two on Vicki's property and two on Bill's, which backs on Vicki's. The nuts are the progeny of a 19" diameter chestnut in Middletown (which was pictured in Plainfield Trees November 21, 2008.) One of the tree's nuts, with newly formed rootlet, is shown below.

The plantings were done with concern for chestnut blight at the forefront. The Madison Avenue chestnut is quite unusual in being absolutely untouched by blight. The last thing anyone wanted was to introduce blight to Madison Avenue with the planting of infected new trees.

Extraordinary measures were taken. First, nuts were planted instead of seedling trees. Why? Unlike seedlings, nuts are extremely unlikely to harbor blight. Second, plant protectors, needed to shelter the tender new trees from predatory deer, were virgin. Sterilizing previously used ones wasn't good enough for us worrywarts. Tony Rosati, a Chestnut Foundation volunteer from Monmouth County, drove out to Hightstown to acquire new ones for use in Plainfield. Third, the nuts were planted only in very close proximity to the Madison Avenue tree. Why? Blight fungi spread on the wind from tree to tree and can also be carried by birds and insects. Spreading chestnut trees around Plainfield could create blight "waystations" that would allow spread of the disease to the Madison Avenue tree.

With luck the new trees might begin flowering in five or six years and cross-pollinate the existing tree so that they can all produce chestnuts. Let's wish them luck.

Chestnut esoterica:
Crown gall, a disease that affects numerous plant species, is caused by Agrobacterium tumefaciens. The name of the bacterium is as ugly as the disease itself, which is pictured below.

I encountered this disease last fall when I bought some hollies to plant on Martha's Vineyard. When I took the hollies out of their pots and "roughed up" their roots for planting, I saw warty, tumor-like growths at the tree bases.

I sent a photograph to American Holly Society trustee Charles Wiley, owner of Vineyard Gardens(1) in West Tisbury MA, who diagnosed crown gall. The disease-causing bacteria enter the plant through a wound near the base of the trunk. The bacteria then engage in genetic engineering. They insert genes into the plant cells that cause the cells to grow rapidly, producing an ugly, tumor-like gall at the tree base. The cells of the gall generate unusual amino acids that are useless to the plant but nourish the bacteria.

What does all of this have to do with chestnut blight? The thuggish bacterial genetic engineers can be co-opted and turned into model citizens. Adopting a technique called Agrobacterium-mediated transformation, researchers at SUNY Syracuse modify the gall bacteria to make them helpful to chestnuts. The scientists replace the genes that direct gall production with genes that are known to be associated with fungus-resistance in some plant species. The modified gall bacteria are then mixed with chestnut embryos. When the modified bacteria inject the chestnut cells, the embryos acquire new genetic material that might help combat chestnut blight. A exciting line of research. See http://www.esf.edu/chestnut/tissue%20culture.htm for more details. (2)

(1) For the record, Vineyard Gardens, a top-notch plant nursery on Martha's Vineyard owned by Charles and Chris Wiley, was not the seller of the infected plants. Having plants infected with crown gall in one's garden is to be avoided. The bacteria persist in the soil and can spread to other plants.

(2) Many thanks to Sara Fitzsimmons of The American Chestnut Foundation and Pennsylvania State University for educating me about Agrobacterium-mediated transformation research on chestnut blight.

Copyright Gregory Palermo

Saturday, January 17, 2009

White Ash

White ash Evergreen Cemetery

Fish gotta swim. Birds gotta fly. Baseball bats gotta be made out of white ash, right?(1) Maybe not. The baseball bat tree is dying off. The very existence of all of our native ash species is in question, threatened by an imported pest called emerald ash borer. The losses to the ash population could be on the scale of the destruction caused by chestnut blight or Dutch elm disease.(2) The insect culprit, first identified near Detroit in 2002, has already killed tens of millions of ash trees in the midwest. Emerald ash borers, metallic green bugs about a half inch long, are headed this way, and they have already been found in western Pennsylvania.

White ash and green ash are both widely used as street trees because they grow fast and are very tolerant of difficult conditions. Plainfield doesn't have a great abundance of ashes, but white ashes, Fraxinus americana, are among our oldest and grandest trees. The two massive white ashes in Evergreen Cemetery on Plainfield Avenue are thought to be more than 150 years old. The one pictured at the top of the page was photographed from Plainfield Avenue. The same tree is pictured below photographed from within the cemetery.

The other ancient ash in Evergreen Cemetery is not visible from the street. It is pictured below.

The Friends of Plainfield Evergreen Cemetery, a volunteer group organized in 2008 by Donald Leichter, plans to rehabilitate the historic graveyard, which has grave markers that date back to the early 18th century. The group hopes not only to restore grave markers and undo the damage caused by vandalism, but also to care for the magnificent trees. We can hope that the volunteers do not find themselves forced to cope with emerald ash borers, but there are weapons available for the fight. Systemic insecticides applied to the soil or injected into the tree annually can control emerald ash borers. These treatments are expensive and are probably suited only to specimen trees. Options available for the large majority of ashes that aren't prized specimens aren't as sure a bet. Researchers are experimenting with parasitic wasps that prey on ash borer eggs and larvae. There are bans on transporting firewood out of quarantined areas to slow down the insect's spread.

Some towns in the midwest have resorted to cutting down healthy ash trees over time before ash borers arrive in order to avoid suddenly finding themselves obliged to remove huge numbers of hazardous ash trees all at once after the borers have killed them. Does this sound extreme? For municipalities weighing their options, Purdue University even offers an online calculator to help determine the comparative costs of tree removal, tree removal + replacement, and antibiotic treatment over a 25 year time frame.(3) A grim calculus.

Adult emerald ash borers live only about three weeks. The females lay their eggs in crevices in ash bark during the summer. The larvae burrow through the bark and spend the next year or two excavating serpentine tunnels through the tree's vascular system, which is just beneath the bark. Destruction of the vascular system prevents the tree from transporting water and nutrients up and down the trunk. Death of the tree typically occurs within five years.

White ash 825 West Front Street
(1) The wood of northern white ash is prized for its combination of strength and light weight. It's perfect for making baseball bats and hand tools. At a time in my life when I thought that a baseball bat was part of the basic required equipment for living, I owned a Louisville Slugger. My friends and I knew that Louisville Sluggers were made of white ash, but we wouldn't have been able to tell a white ash tree from a white spruce. I don't know what ever happened to my Louisville Slugger, but these days I get plenty of use out of ash in the form of garden spade handles. It must be admitted that it's hard to work up the same enthusiasm for a spade that a bat can inspire. Recently maple bats have become popular. Many professional baseball players switched to maple bats when it became known that maple was the choice of Barry Bonds (http://www.nytimes.com/2007/07/11/us/11ashbat.html).

Copyright Gregory Palermo

Friday, November 21, 2008

American chestnut

Needed: a photograph of an American chestnut to be enlarged to a height of two stories for a museum exhibit about chestnut trees and the Appalachian mountains. Where do you suppose the paragon of chestnuthood worthy of such photographic extravagance was found? Why, suburban New Jersey, of course. The photogenic chestnut is shown below with its discoverer, Tony Rosati, and his border collie, Jessie. The tree is 19" in diameter at chest height and is next to a path through the woods behind the Middletown Public Library. Mr. Rosati discovered the tree a few years ago while he was strolling in the woods with Jessie, just killing time while waiting for a canine agility training course.

The black discolorations on the tree's bark are the result of chestnut blight. More detail of chestnut blight injury can be seen in the photographs in Note 4.

Tony Rosati was in Plainfield a few weeks ago to visit our own American chestnut, a 10" diameter tree at 946 Madison Avenue. The tree was planted in 1992 by Bill Santoriello and is now owned by Vicki Blasucci. Robin Gates wrote to report on the existence of this tree as a correction to my September 2007 blog posting on chestnuts ( http://plainfieldtrees.blogspot.com/2007/09/chestnuts.html ). My posting had made the (seemingly safe, but erroneous) assertion that one probably had to leave Plainfield to see an American chestnut.

The Madison Avenue chestnut has become a star. Someone posted forty photographs of the tree on Flickr http://www.flickr.com/photos/njheart2heart/sets/72157609014062777/ . Members of the Pennsylvania chapter of the American Chestnut Foundation are interested in the tree because it has reached a considerable size(1) in good health and with a graceful shape. Past president of the chapter Bob Summersgill recently visited the Madison Avenue chestnut. He concluded from a quick inspection that there were no other chestnuts in the vicinity. How did he know that? He had two important clues. First, the tree had no injury from chestnut blight, which it almost surely would have had if there had been a nearby chestnut to transmit the infection. Second, the tree was producing only sterile burs, lacking a nearby chestnut to serve as a pollinator. Mr. Summersgill showed me the papery "non-nuts" inside the unfertilized burs (pictured below).

Unfertilized chestnut bur with papery, brown "non-nuts" in the center. Even the squirrels have no use for them.

Rosati and Summersgill have great hopes for the Madison Avenue chestnut. They would like to provide pollen for the tree so that it can reproduce. The flowers could be hand-pollinated with pollen from another chestnut. Alternatively, blight-free chestnut seedlings could be planted nearby, and the wind could do the work of pollination.

Rosati and Summersgill's work was featured in the October 9 edition of the Star-Ledger.(2) The article focused on American chestnuts in the Monmouth County parks, some of the best surviving examples of the species in the eastern United States. Volunteer workers hand-pollinate the chestnut flowers in the spring, bag the flowers to keep out other pollen, and harvest the resultant bagged chestnuts in the fall. This is not work for the faint of heart. Chestnuts only produce flowers on branches that are exposed to the sun. For a tree in the woods, that means the top branches only. The volunteers go up as high as 75 feet in a cherry-picker to accomplish their mission.

But this is New Jersey; there must be another twist to this story. What do the chestnut harvesters do with the chestnuts that they collect? They plant some of them in the garden of Vito Genovese, (now Deep Cut Gardens, part of the Monmouth County parks system, the garden was created by Vito Genovese). Yes, that Vito Genovese. Reputed to be the convener of the ill-fated 1957 mob conference in Apalachin New York, Vito Genovese is also said to be the man who ordered the barbershop assassination of Murder, Incorporated's Albert Anastasia.(3) When Mr. Rosati took me to visit the little chestnut nursery at beautiful and peaceful Deep Cut Gardens, I could sense the spirit of Vito Genovese watching over the tender saplings and frightening off predatory deer.(4)

(1) A considerable size by the standards of today. American chestnuts used to mature at trunk diameters many times the size of the Madison Avenue tree's.

(2) http://www.acf.org/pdfs/news/2008/LastStandForTheOldChestnut.pdf
The Monmouth County chestnut work cited in the article is a collaborative effort involving the Monmouth County Park System, The Monmouth County Shade Tree Commission, the Middletown Parks and Recreation Department, and the Pennsylvania chapter of the American Chestnut Foundation.

(3) http://en.wikipedia.org/wiki/Vito_Genovese

(4) American chestnuts are sometimes able to survive chestnut blight until they're old enough to produce nuts. In addition, the stumps of fallen chestnuts send up new shoots that mature to bear nuts. All other things being equal, the species might presumably limp along that way until it develops resistance to chestnut blight through genetic mutation. The explosion of the deer population has placed another obstacle in the way of hopes that the species will escape extinction, however. Deer are very willing to eat chestnut shoots.

While I can't claim to keep up with the research, I know of several avenues along which workers hope to develop blight-resistant American chestnuts. 1. Breeding the Chinese chestnut's resistance into American chestnuts. The American Chestnut Foundation has a program that crosses Chinese chestnuts with Americans to confer resistance and then "backcrosses" the progeny with Americans over several generations to dilute out the Chinese characteristics while maintaining the blight resistance. 2. Other researchers are using molecular techniques to decipher and/or modify chestnut DNA. 3. Hypovirulence: weakening of the chestnut blight fungus with an antifungal virus. 4. Natural resistance. It's not clear why Monmouth County's parks have American chestnuts that survive better than American chestnuts elsewhere. Perhaps they have evolved some measure of blight resistance. It's just possible that Tony Rosati and coworkers will produce a highly blight-resistant strain in their little chestnut nursery in Deep Cut Gardens. If they do, I will lobby hard to persuade them to name it Castanea dentata 'Vito Genovese'.

The blackened areas on the trunk pictured above are the sequelae of chestnut blight.

Damage from chestnut blight at the tree base.

Damage from chestnut blight

Copyright Gregory Palermo

Monday, September 29, 2008

Red oaks

It's not a matter of black and white! The two young oaks pictured above are a white oak and a black oak growing in the woods in Edgartown Massachusetts. To label them black and white seems like quite an exaggeration, but the trees are so called because of their bark color. (The lightest flecks on both trees are lichens, not bark.)

The complex oak genus has hundreds of species. Many of the species complicate life for classifiers by cross-breeding with each other. Botanists divide the oaks into two groups: the white oak group and the red/black oak group.

The majestic northern red oak, one of the two headliners of the red/black oak group, is New Jersey's state tree. Plainfield is blessed to have many beautiful examples. Red oaks are the fastest growing of the native oaks. We shouldn't be surprised that red oaks are some of the largest trees in Plainfield.

There is a very fine red oak at 916 West Eighth Street, pictured above. How to recognize it as a red oak, Quercus rubra? First, you can put it in the red/black oak group by observing that the lobes of the leaves end in points, (bristle tips). The leaf lobes of the white oak group, by contrast, are rounded. The photograph below shows a red oak leaf on the left and a white oak leaf on the right. The bark color also helps in assigning a group.(1)

That's a start, but how do we know that it's a red oak, and not another member of the red/black group? How do we distinguish it from a pin, scarlet, or black oak? Like red oaks, all those other three species have lobed leaves with bristle tips, and all can be found in the Plainfield area. Red oak leaves are easily distinguished from pin (Quercus palustris) or scarlet (Quercus coccinea) oak leaves because the red oak leaves are much larger. Their lobes are also much less deeply cut. The large acorn and the leaf on the right in the photograph below are from a red oak. The leaf on the left is from a pin oak.

Black oaks (Quercus velutina) can be more difficult to distinguish from red oaks. Black oaks have large leaves, but the leaves are more leathery and lustrous than red oak leaves. Unfortunately, they interbreed quite readily with red oaks, so it's hard to know sometimes whether or not you're really looking at a black oak. (2) Other features of the trees can help with speciation. Red oaks have much larger acorns than black oaks. Red oak acorns have a distinctive look, with a very shallow, saucer-like cap. Mature red oak bark is described as resembling interweaving ski tracks.

Another very handsome, mature red oak is at Stelle Avenue near Central. This magnificent street tree was the subject of some concern two or three years ago when the owner of the adjacent Coriell mansion proposed to restore the semicircular driveway that had once opened onto Stelle Avenue. The driveway was to encircle the red oak. Because the house was being converted to a B & B, the fire department wanted the driveway to be wide enough to accommodate fire trucks. The Historic Preservation Commission intervened to have the driveway narrowed so as to limit damage to the tree's roots.

The handsome red oak at the corner of 1300 Prospect Avenue at the corner of Hillside has a vase-like shape reminiscent of that of an American elm.

The massive red oak at 947 Fernwood pictured below was given special recognition as a specimen tree by Mayor Robinson-Briggs at this past April's Arbor Day celebration.

Another very fine red oak is at 912 Central Avenue. I measured its circumference today at 17 feet at breast height.

(1) Bark color is not necessarily a reliable indicator. Chestnut oak (Quercus prinus or Quercus montana), a member of the white oak group, has bark that is quite dark gray, an exception to the general rule that trees of the white oak group have light-colored bark. The chestnut oak pictured below is on Park Avenue near Randolph Road, across the street from Muhlenberg Hospital. See the January 13, 2008 posting of Plainfield Trees for additional differences between oaks of the white and red/black groups.

(2) The Trees of Pennsylvania and the Northeast, Charles Fergus, Stackpole Books 2002, p. 113.

Copyright Gregory Palermo

Friday, August 22, 2008

From Tree Hugger to Bug Hugger

Is your sleep disturbed by worries about disappearing spotted owls and snail darters? Maybe the objects of your concern are too grand. What you should really be worrying about is bugs: native bugs and the native plants that sustain them. That is the argument advanced by professor of entomology Douglas Tallamy in his recent book, Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens.(1) He says that we are starving our insects by replacing the native plants that they eat with exotic plants that they can't even recognize as food.

Native sweetbay magnolia. Native insect? Click to enlarge.

Starving the bugs sounds like a great idea, right? Maybe not. Tallamy presents insects as unloved heroes that transform the stored energy in plants into food (themselves) for the next level up in the food chain. In order to transform themselves into bird food, for example, insects must have food of their own to eat. But we are depriving them of food by replacing the native landscape with foreign plants. The vast majority of our insects are dietary specialists; the only foods they are capable of eating are members of the native plant community with which they have co-evolved over millions of years. Those are the foods to which their anatomy and physiology are adapted. They have as much success eating foreign plants as we would have if we tried to adopt the koala bear's diet of eucalyptus leaves. Without native plants, the insects have nothing they can eat, and they perish. With the insects gone, all of the food chain above insects will collapse.

American elm 1267 Park Avenue

The differences between the numbers of insects that can eat native versus foreign plants can be startling. Native oaks can provide food for over 500 different native insect species. Eucalyptus, an exotic, is eaten by only one native insect species. Native plants in Pennsylvania were found to support 35 times more caterpillar biomass, the preferred source of protein for most bird nestlings, than alien plants supported.

Native northern red oak, New Jersey state tree, West 8th St

How big a problem can this insect starvation be? Biodiversity depends on space. The more space, the larger the number of species that can be supported. The relationship is linear.(2) Only 3-5% of the lower 48 states remains undisturbed habitat for plants and animals. The rest has been paved, farmed, taken over by noxious foreign weeds like kudzu and Japanese honeysuckle, or transformed into suburban gardens dominated by exotic shrubs and vast lawns of non-native grasses. Tallamy points out that suburban lawns cover about 62,000 square miles of this country, an area more than eight times the size of New Jersey that is devoted to alien grasses.(3) Worse, 43,000 square miles of blacktop has been spread over the landscape, equal to five and a half New Jerseys. If we have eliminated much of the native vegetation from 95-97% of the American landscape, we can expect to lose 95-97% per cent of our native flora and fauna over time, as extinction adjusts the number of species to the land area that remains. Tallamy cites the toll of habitat destruction on Delaware, where he teaches. As of 2002, Delaware had lost 78% of its freshwater mussel species, 34% of its dragonflies, 20% of its fish species, and 31% of its reptiles and amphibians. Forty per cent of all native plant species in Delaware are threatened or already lost.

American holly East 9th Street

At this dismal point in his book Tallamy offers a ray of hope: suburban gardeners to the rescue! If suburbanites, who control a large swath of the landscape, were to plant native plants on their properties, the countryside could still support a diverse flora and fauna. Mix some American elms in with all those Zelkovas. Make your lawn smaller, and plant a meadow. Tear out some of your English ivy and Japanese pachysandra and plant mayapples. I repent ever having written that foreign, kousa dogwoods have the advantage of not being attacked by the borers that plague native flowering dogwoods (a good example of just what Tallamy is talking about). How petty of me ever to have planted exotic hollies instead of American hollies because of the Americans' problems with leaf miners! I'm going to be beating myself up for years over this. But as part of my rehabilitation program, I will spread the word about Tallamy's book, essential reading for anyone who plants.

Native black walnut leaf nibbled by, no doubt, native insects

(1) Tallamy, DW. Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens. Timber Press, 2007.

(2) Tallamy cites the work of Michael Rosenzweig at the University of Arizona to support his claim that species diversity decreases in proportion to the loss of available space. His very cursory discussion of this important underpinning for his argument is, for me, the weakest part of his book. I would like to have seen Rosenzweig's data and analysis described in detail.

(3) If you would object that Kentucky bluegrass is a native, you would be mistaken. Its seeds were imported by European settlers in the digestive tracts and droppings of cattle.

Copyright Gregory Palermo

Thursday, July 24, 2008

Black walnut

What do walnuts, Wales, Walloon, Welsh, Walsh, Wallace, and Cornwall have in common? The words all indicate foreignness.

Walnuts are foreign nuts, and the "wal-" in their name indicates that fact. Foreign to whom? To the English. The American Heritage Dictionary explains the history nicely: "Although Celtic-speaking peoples were living in Britain before the arrival of the invaders...whose languages would eventually develop into English, it was the Celts and not the invaders who came to be called 'strangers' in English. Our words for one of the descendants of the Celtish peoples, Welsh, and for their homeland, Wales, come from the Old English word wealh, meaning 'stranger'.... Old English...walhhnutu [exists] in a document from around 1050.... This eventually became walnut in English...literally the 'foreign nut.' The nut was 'foreign' because it was native to Roman Gaul and Italy."(1)

Black walnut (Juglans nigra) is an American native closely related to the Persian walnut (Juglans regia) of Europe and Asia. It grows wild in the eastern United States except for parts of New York and New England.(2) The tree is highly valued for its wood and for its nuts. The wood is so valuable that black walnuts are at risk of being felled and stolen by "walnut rustlers." For that reason, I won't specify the locations of the pictured Plainfield trees. Walnuts have been prized since ancient times. The Romans esteemed them highly enough to call them Jupiter's nut (Jovis glans) from which the scientific name Juglans derives.(3)

Walnuts have pinnately compound leaves (with leaflets arranged like a feather), each leaf a foot or two in length and made up of as many as 23 leaflets. The leaflets are serrated, and the leaflet at the tip of the leaf is often undersized or missing, a useful feature in identification. The leaves emit a spicy odor when crushed. They turn yellow in the autumn and are among the earliest leaves to fall.

The bark is dark gray-brown and deeply furrowed, forming diamond shapes.

The nuts fall around the same time as the leaves and are covered by a fleshy green hull that will stain your hands black if you try to remove it. Breeders have produced over 500 varieties of black walnut, trying to create nuts with a thinner shell and a less convoluted inner structure so that the kernel is easier to extract.

Almost as well-known as its delicious nuts and its beautiful wood is walnut's toxic effect on neighboring plants. This effect has been known for millennia. Pliny the Elder wrote in the first century AD that, "the shadow of walnut trees is poison to all plants within its compass." Juglone, the toxin that the tree produces to keep the rest of the natural world at bay, is present in leaves, branches, bark, roots, and nuts. The chemical is toxic to a variety of other plants. Don't, for example, plant tomatoes near a walnut tree. The toxin's victims are not limited to plants. Bruised walnut leaves and branches have been put into water by fishermen to stun fishes.

(1) The American Heritage Dictionary of the English Language, Houghton Mifflin Company 2000. See the entry for Wales.

(2) Edward Goodell, Walnuts for the Northeast, Arnoldia 44: 1-19, 1984.

(3) The Romans' walnut was Juglans regia, Persian walnut. It is also called English walnut. But, as discussed above, there really is no such thing as an English walnut.

Copyright Gregory Palermo