292 OHIO BIOLOGICAL SURVEY 



chance, a few leaves fall around it, the petioles bend up nearly to a 

 vertical position, raising the leaves to a certain extent above the 

 obstruction. 



As in every other guild of plants, the members of this one are not 

 all typical, but intergrade with various other guilds, from lianes to 

 rosette plants, and in so far as they depart from the characters of the 

 guild, they escape its limitations. Some of them, like the partridge 

 berry, Mitchella repens, have a sufficient power of growth to raise 

 themselves above a leafy blanket which may be heaped upon them. 

 Thus, though normally prostrate, this plant forms ascending shoots a 

 decimeter or two high when it is buried under leaves. Nevertheless, its 

 distribution is largely controlled by this one factor. It is perhaps 

 most at home on sloping boulders and the edges of banks, but covers 

 the ground in the hemlock forest where the falling leaves are so small 

 as to pass down between its blades. In one case it was found even 

 in the deciduous forest on a pile of stones, only a decimeter or so in 

 height, but just sufficient to stand out from among the leaves. Others, 

 like Hepatica or Polystichum, send up their new leaves so early in the 

 season that even w^hen covered up the handicap is soon thrown off. In 

 such cases, covering beneath fallen leaves means simply the loss of 

 photosynthetic activity during the winter, which might be supposed 

 to be inconsiderable. Nevertheless these plants usually attain their best 

 development in places too steep to permit the accumulation of leaves 

 upon them. Still others, like the wintergreen, Gaultheria procumhens, 

 are not strictly prostrate, but in their aerial parts approach more 

 nearly to the upright condition. This plant, together with some others, 

 is an Oxyphyte, and this character combines with the one under dis- 

 cussion to limit it to situations free from leaf fall. 



Doubtless all of the ordinary biennial rosette plants, such as the 

 shepherd's purse, would likewise be sensitive to a covering of leaves, 

 but with them this is not an important factor because they are sun- 

 loving plants of exposed situations, where leaves would never accumu- 

 late in any case. It is only for plants growing beneath the forest canopy 

 that this factor can become of importance. 



The plants of the Sugar Grove area which belong to this guild are: 



1. Typical shade-loving evergreens with leaves appearing late in 



the season : 



Peramium pubescens Folypodium vulgare 



Pyrola elliptica Epigaea repens (fig. 17) 



Camptoforus rhizophjiUus (i\g. 26) 



