THE POLYPODIES 91 



into three branches, each of which is triangular 

 in shape and pinnate towards the base, be- 

 coming pinnatifid at the tip. The pinnae are 

 deeply segmented. The unrolling of the frond 

 is a very novel feature of this Fern, each branch 

 at this time appearing to be like a small coil of 

 wire. In its early days the golden green colour 

 of the frond is very much pronounced, but as the 

 leaf ages a deeper tone is assumed. 



The sori are disposed near to the margins of 

 the lobes of the leaves, and these are circular 

 and without indusia. The lower pinnae of the 

 Oak Fern do not point downwards, as is seen in 

 the case of the Beech Fern. 



The Oak Fern is common in many parts of 

 Scotland, and is to be seen carpeting the ground 

 of many a moist wood. It also occurs in Eng- 

 land chiefly in the northern counties. In some 

 parts of Wales it is to be found in plenty, but 

 the species is said to be rare in Ireland. The 

 Oak Fern grows in a damp and shady spot in 

 the garden, though it is often more happy in a 

 pot. The fronds of the plant die down in winter, 

 and the fresh ones do not start until late in the 

 spring. 



In some books a species called Polypodium 

 calcareum (The Limestone Polypody) is described. 

 In some quarters this plant is regarded as a 

 variety of P. dryopteris, as it is similar in some 

 respects. Mr. C. T. Druery considers it to be a 

 distinct species. The chief points of difference 

 are said to be the following. The whole plant 

 is larger in growth, whilst the green of the 

 fronds is not such a golden colour, even in the 

 early days. Also the pinnae are not arranged so 

 definitely in the form of three branches, as is to 

 be observed in the case of the Oak Fern. Finally , 

 the unrolling of the frond does not present the 



