Wednesday, January 11, 2012

American Chestnut

From Wikipedia:
"Once an important hardwood timber tree, the American Chestnut is highly susceptible to chestnut blight, caused by an Asian bark fungus (Cryphonectria parasitica, formerly Endothia parasitica) accidentally introduced into North America on imported Asiatic chestnut trees. The disease was first noticed on American Chestnut trees in what was then the New York Zoological Park, now known as the Bronx Zoo, in 1904 by chief forester Hermann Merkel. While Chinese Chestnuts evolved with the blight and developed a strong resistance, the airborne bark fungus spread 50 miles (80 km) a year and in a few decades girdled and killed up to three billion American Chestnut trees. It is thought that panic logging during the early years of the blight may have unwittingly destroyed trees which had resistance to this disease and thus aggravated the calamity."

I've visited this tree previously with a leaf drawing and a summer view. In years gone by the road would be peppered with spiny pods from this tree.

Here's a closer look at the stump sprouts.

Some of these sprouts are sadly already dying off.

More from Wikipedia:
"The fungus makes its entry at wounds and grows in and beneath the bark which eventually kills the cambium all the way round the twig, branch or trunk. The first symptom is a small orange-brown area on the bark of a twig or branch. A sunken canker then forms as the mycelial fan spreads under the bark. As the hyphae spread they produce several toxic compounds, the most notable of which is oxalic acid. This acid lowers the pH of the infected tissue from around the normal 5.5 to approximately 2.8, which is toxic to plant cells. The canker eventually girdles the tree, killing everything above it. Distinctive yellow tendrils (cirrhi) of conidia can be seen extruding from the stroma in wet weather."


  1. Chestnut blight literally changed the face of the New England landscape- it is amazing to look at old vintage photos and see the massive old chestnuts that literally canopied the main streets of our villages and towns. I'm guessing that any chestnuts that managed to survive the blight and subsequent panic logging probably were taken down by the Hurricane of '38. The high winds of the hurricane probably helped spread the blight further north as well. Amazing (and sad) to see the blight still affecting trees all these years later.
    ~ gretchen

  2. I am amazed at how far a tree can mature and still be affected. I'd always suspected that blight took this tree but it wasn't until getting the orange photos earlier this week that I could look it up and confirm.

  3. Really nice picture, and fungi symptoms.:-)

  4. Thanks, biolover. Perhaps one day you will find a way to stop this fungus! :-)