WOODSIA. 187 



are almost concealed. The stipes is also scaly, and, as 

 occurs in a whole group of these Woodsias, has a joint or 

 articulation at a short distance from its base, at which 

 point separation takes place if the fronds are left to attain 

 a good old age, the lower part remaining attached to the 

 caudex, while the upper part falls away. The veining of 

 the segments of the pinnae consists of a rather indistinct 

 midvein, from which the veins, either simple or branched 

 proceed towards the margin, near to which the sori are 

 produced. 



There seems no reasonable doubt that the Fern which 

 Linna3us called Acrostichum ilvense is that now under 

 notice. It has also been called Pohjpodium ilvense. 



Woodsia alpina, Gray. 



The Blimt-leaved, or A Ipine Woodsia. 



(Plate IV. fig. 1.) 



This is a diminutive species, never exceeding a few inches 



in stature, and renewing its fronds annually in the spring, 



the older ones being destroyed by the frosts and cold of 



winter ; when this influence is felt by the plants, the fronds 



quickly lose their vitality, and are cast off at the articulation 



or joint near the base of the stipes, which occurs in this 



