THE SLENDER CLIFF-BRAKE 



'T'HE fern collector who finds the slender cliff-brake in his 

 locality may consider himself fortunate. The species is 

 not one of those elusive ones that occur sparingly here and 

 there and are therefore likely to be overlooked ; it often grows 

 in great abundance where it occurs at all but it is not found in 

 every place that appears suited to it, and in short, it is one of 

 those plants which the botanist writes down as local without 

 being able to discover what it is in the soil, surroundings, or 

 plant predilections that makes it so. 



It is the general impression that this plant is always associ- 

 ated with limestone rocks, but recently it has been reported 

 several times on sandstones and more rarel)^ on shales. Possibly 

 one of the reasons it seems to prefer limestones is because such 

 rocks are not only more likely to afford perennial supplies of 

 moisture but they also prov ide the little ledges and shelves of 

 rock on which the fern delights to grow. Many, perhaps the 

 majority of plants that grow on cliffs, are true xerophytes and 

 can get along with the minimum amount of water, but the cliff- 

 brake is a mesophyte and is seldom found far from abundant 

 moisture. If one hopes to find it in his locality he should search 

 all the dripping ledges of limestone. 



Although the cliff-brake is one of the smallest and most 

 delicate of our ferns, it elects to grow in the colder parts of the 

 world and encircles the earth north of the parallel of 40 degrees. 

 North Latitude. Its farthest southern stations are in northern 

 Pennsylvania, Illinois and Iowa but in all these States it is 

 extremely rare. Nearer the Pole, however, it often completelv 



