BOTANICAL SURVEY— SUGAR GROVE REGION 



291 



possessed by all evergreen undergrowth in being able to carry on photo- 

 synthesis during the months when the trees are bare. But they laboi- 

 under a disadvantage which very stiikingly limits them to a peculiar 

 class of habitats — namely, those which are free from a covering of 

 fallen leaves. 



The sitimtion will be evident from the consideration of a typical 

 case, that of the Rattlesnake plantain, Peraininm puhesceus (fig. 25). Its 

 rosettes of leaves do not appear until late in the season, but persist 

 through the winter and well into the following season. With its pros- 

 trate stem fixed on the ground, antl its slow growth, it has no means of 

 surmounting a covering of leaves, so that if deeply covered it is 

 inevitably smothered. Not only is it deprived of light during the 

 winter; it seirds up no erect shoots to pierce the leafy blanket in the 

 spring. The plant grows in vai'ied habitats, such as ]-ocks, hemlock 



Fig. 25. Rattlesnake Plantain (Peramiuni pubescens) on a Boulder in the Forest. 



forests, bare soil, and the lianks of streams. Young plants nray be foun 1 

 almost anywhere, as would be expected from seeds scattered by the 

 wind, but well-dev(doped clumps are only to be found in situations 

 remaining nearly free fiom a winter covering of leaves. Wlrerr, per- 



