Showing posts with label Chestnut. Show all posts
Showing posts with label Chestnut. Show all posts

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."

Saturday, December 19, 2009

American Chestnut

There is something to be said for sharp pencils, 2H and HB. I had an awful lot of fun with this chestnut leaf, for about four hours. Next day I wanted to get back at it for some tweaking but decided to let it stand as is and move onto something new. I learned a lot with this one.



Thursday, July 30, 2009

American Chestnut

Here is a victim of the chestnut blight. Since the early 1900's the American Chestnut, Castanea dentata, has in many cases been killed off by that nasty fungus.


What I like about this tree is its determination to survive. Although everything above the main trunk had died off, there are sprouts from the trunk reaching out.



It's a short post today--finally wrapped up late night new car shopping! Phew, glad that's over...