FAIRY-RINGS FORMED BY LYCOPODIUM INUNDATUM. 



WHILE visiting on the 20th of July, 1S9S, the sandy shores 

 of Gilmore pond near Jaffrey, X. H , I was attracted by 

 fome exceptionally fine specimens of the dwarf club 

 moss (Lycopodium inundatum) . This species is reputed rather 

 rare in America, but it has already been noted at a considerable 

 number of stations, and where it occurs at all it is apt to be abun- 

 dant. The striking feature of the specimens observed was that 

 they grew in more or less definite rings, not unlike the so-called 

 "fairy-rings" formed by various species of fungi. More than 

 fifty of these rings were observed, together with various regular 

 and irregular patches and segments of curves. The rings varied 

 from 7dm to 4m. in diameter, the circumference being formed by 

 a more or less regular band of prostrate vegetative shoots, which 

 at the numerous forkings threw up abundant fertile stems. 



Slight examination showed that the rings developed in a most 

 natural way. A young plant, starting from a centre, sends out 

 its prostrate forking stems in all directions, until soon a small 

 patch of ground is pretty uniformly covered with the stems. 

 These areas, although subject to irregularity from obstructions, 

 are usually about circular. Several were observed which were 

 from 2.5dm. to 4dm. in diameter. Now, it is a well known fact 

 that the prostrate stems of Lycopodium inundatum, as they grow, 

 constantly root near the tip, while the older parts begin to die and 

 decompose. With this mode of growth and the early tendency of 

 the stems to develop radially or centrifugally, the formation of the 

 rings is at once explained. The older parts of the plant, which 

 are at the centre, are the first to die away, and what is left is a 

 ring of separate, diverging branches of what was once a single 

 plant. These continue to grow as independent individuals. The 

 size of the ring is thus an approximate indication of the age of 

 any particular colony. The stems appear to grow from 2 to 

 3. 5dm. in one season ; a ring would, therefore, add nearly a foot 

 to its radius each year, and its age be roughly found by halving 

 its diameter expressed in feet. 



It is not maintained that the rings are always so perfect as 

 our theory would make them. There are several obvious sources 

 of irregularity. The chief of these are the crowding of other 

 plants, inequalities of the ground, and especially the fact that 

 neighboring rings often become confluent and confused. How- 

 ever, making all due allowance for irregularities, the rings on the 



