Another report of Marchantia polymorpha 

 after forest fires 



Raymond H. Torrey 



A note by the writer in a recent number of Torreya, on the 

 extensive occurrence of Marchantia polymorpha after a forest 

 fire on Kittatiny Mountain, in Warren County, New Jersey, 

 has brought the following letter from Mr. William W. Diehl, 

 Associate Pathologist, Bureau of Plant Industry, United States 

 Department of Agriculture, Washington, D. C: 



Your note on 'Marchantia polymorpha after forest fires' in 

 the first number of Torreya for this year is very timely to recent 

 observations of mine. 



On June 12, I was botanizing on the top, of Old Rag Moun- 

 tain (Ragged Mountain) in Virginia, near Hoover's Camp, and 

 was surprised at the great amount of Marchantia polymorpha, 

 in some places covering an acre or more. The entire area had 

 been burned over very badly some time during the past year 

 so that I assumed then that Marchantia might well be one of 

 the early comers after fires. This was of special interest to me 

 in that I had the impression that Marchantia is generally 

 thought of as rare in the southern Blue Ridge. 



The large colonies of this hepatic, which I found on Kitta- 

 tiny Mountain in autumn of 1931, a year after a great forest 

 fire, which devastated over 3,000 acres, still remain, although 

 some what less extensive now that new herbaceous and shrubby 

 growth is returning. Their sudden and widespread seizure of the 

 open areas of charred humus and thin mineral soil is puzzling to 

 me, when it is considered that the dispersal of the spores of 

 Marchantia is by means of hygroscopic elaters. One would not 

 expect this method to scatter the spores more than a few yards 

 from the parent plants.* I have usually found this hepatic in small 

 colonies along brooks and on peat bogs. There are brooks and 

 small swamps on Kittatiny Mountain, 200 to 400 feet below the 

 highest ridges, where it might have occurred. But within less 

 than a year after the fire, which occurred in August, 1930, Mar- 

 chantia overspread large areas on the burned soil, with thalli 

 several inches in diameter, confluent so as to completely and ex- 



*Note by editor. It is probable that the elaters force the spores from the 

 capsules when the wind causes changes in the humidity of the air and that, 

 once out, the wind carries the spores. 



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