Vol. XI Washington, D. C., October 29, 1917 No. 5 
FUNGUS FAIRY RINGS IN EASTERN COLORADO AND 
THEIR EFFECT ON VEGETATION 
H. L. Shantz, Plant Physiologist, 2nd R. L. PiEMEiSEL, Scientific Assistant, Alkali 
and Drought Resistant Plant Investigations, Bureau of Plant Industry, United States 
Department of Agriculture 
INTRODUCTION 
The present paper deals with fairy rings caused by fleshy fungi. The 
rings due to other causes, such as the grass rings, are not considered. 
The fungus rings are marked either by the fruiting bodies of the fungus 
or by a stimulated or a depressed growth of the natural vegetation or 
the cultivated crop. Fairy rings may become so abundant locally as 
to affect materially the crop yields of fields. On lawns they cause 
unsightly bare spots and dark-green areas, and in small experimental 
plots cause either a total loss of crop or a greatly increased yield. They 
are undesirable in all cases, and their eradication is a matter of practical 
importance. The studies herein recorded were made on the High Plains 
at Akron, Colo., during the period 1907 to 1916, inclusive. The soil 
studies were made during the summers of 1914, 1915, and 1916. The 
native vegetation at Akron has already been described in some detail 
(Shantz, 1911). 1 It is typical short grass, composed largely of Bouteloua 
gracilis ( oligostachya ) and Bulbilis dactyloides . 
The term “fairy ring/' generally used to describe the arrangement 
of plants in an approximately circular form, originated in the belief that 
these circular growths marked the paths of dancing fairies. Early 
literature is filled with tales of superstition concerning these rings. The 
superstitions varied somewhat with the different countries. In Holland 
these circles often marked the places where the devil churned his butter. 
The presence of such a ring on a farm caused an inferior quality of butter 
if the cows ate the grass from a fairy ring. In France many people could 
not be induced to enter one of these rings, because enormous toads with 
bulging eyes abounded there; but no harm was experienced if the rings 
were unintentionally entered at night. In Sweden a person entering a 
fairy ring passed entirely under the control of the fairies. Treasures were 
marked by such rings in many places, but these riches could not be 
secured without the help of fairies or witches. In England it was regarded 
1 Bibliographic citations in parentheses refer to “Literature cited,” p. 243-245, 
(191) 
Journal of Agricultural Research, 
Washington, D. C. 
kf 
Vol. XI, No. 5 
Oct. 29,1917 
Key No. G—124 
