148 HISTORY OP BRITISH FERNS. 



of these seems to have the precedence on the ground of 

 priority, but it has not as yet been adopted in this country. 

 POLYPODITJM DRYOPTERIS, Linnaus. The Tender Three- 

 branched Polypody, sometimes called the Oak Pern. (Plate 



ii. % i.) 



This is at once known among the Polypodies by having 

 its quite smooth fronds divided into three branches; and 

 when the fronds are but partially developed this latter cha- 

 racteristic is available, for the three branches are rolled up 

 separately, and the fronds in the stage alluded to resemble 

 three little balls set on short slender wires, and supported 

 by one which is longer and stouter. It is, however, alto- 

 gether a slender and delicate plant, its height being com- 

 monly not more than six inches, often less, arid sometimes 

 more, its colour a pale bright green, and its texture fragile. 

 Hence it is at once destroyed by frost, and soon becomes 

 rusty and withered by exposure to heat and drought. When 

 growing in a cool, shady situation, however, it continues 

 fresh and cheerful-looking from April, when it usually starts 

 into growth, onwards until it is affected by autumnal cold. 

 In pots, in Wardian cases, or on sheltered, shady rock -work, 

 it is alike desirable for cultivation. 



The fronds of this delicate little Pern grow from a slender 



