Wednesday, January 27, 2010

Interesting Xylariaceae Found

During a collection event in June 2009, I came across a very interesting resupinate fungus.  The fruiting body was spreading across the barkless surface of a large downed tree.  I had seen many resupinate fruiting structures during my two years of research, however the gray center and white colored margin of this fungus caught my eyes from nearly ten meters away.  Upon closer examination, this fungus appeared to be in a state of active growth.  Later, this observation would be confirmed with images and descriptions of the lifecycle of this fungus provided through multiple resources.  You might be asking yourself what fungus I have been mentioning.  Kretzschmaria sp. cf. deusta  (Hoffm.) P.M.D. Martin is the proposed name for this collected specimen.  This species of fungus is common, but is often overlooked once the dark black stroma gives it's substrate a burnt appearance.  The fungus causes rot of trees and is often located at the base of infected trees.  Infected trees become quite brittle and should be monitored as they are prone to structural failure with little to no warning.  The upper right image was taken during the immature or actively growing state of this fungus.  The second image allows one to see the mature fruiting structure with the embedded perithecia creating a pimpling of the stroma surface.  A stereoscopic image of the stroma in cross section showcases the perithecia and the asci found within them.  A wet mount was prepared from tissues extracted from the opened perithecia and spores exhibiting classic Xylariaceae characteristics were observed.  The final image clearly shows the narrow, dark-brown to black spores.  The spore size was 32x8 micrometers with a smooth texture and central germ split.    DNA from the collected specimen will be extracted and amplified using PCR.  The PCR product will then be sequenced and this ITS sequence will be entered into a BLAST search to aid in its identification.  Keep an eye open for this very interesting fungus during your next hike through the forest.  Click on the title of this post to view other images of this fungus!

1 comment:

  1. I enjoyed reading this post, great pictures! --Sara May