CL. XXIV.] 36. BLECHNUM BORKAI.E. U7 



CLASS XXIV. 



I. True Ferns, 



Blcchnum borealc, Stv, 



Nordlicher Rippenfarrn. 



This handsome fern grows in our woods. The root \% 

 about the thickness of a Uttle finger, of a brownish red colour, 

 covered with scales, chaffy leaves, and the remains of old 

 stalks. It pushes downwards fibrous roots, which are ex- 

 panded on all sides. From the root arise the fronds, at first 

 of a snail-shape, and every where set with hairs and chaffy 

 leaves. Afterwards these last-mentioneil substances disap- 

 pear in a great measure, so that the mature stalk is only fur- 

 nished at its lov/er part with a few scattered chaffy leaflets. 

 The fronds are partly fertile, partly barren. These last arc 

 from a large span to a foot in length, lanceolate, deeply half- 

 pinnated. The kciniae alternate in such a manner, that one 

 is always in the centre of two others that are opposite to it, 

 and, when seen from above, it seems to unite with them. 

 The lacinias are from half an inch to eight lines in lengthy 

 quite smooth and entire, somewhat falcated, pointed or some- 

 what obtuse, and penetrated by a principal nerve and piu'al- 

 lel veins. The lower laciniae are always more obtuse, rounder 

 and shorter, the wider they stand ; the uppermost unite into 

 one entire point. The stalks of these barren shoots are sharp, 

 angular, yellowish brown below, and become whitish where tlie 

 frond begins ; but sometimes also the yellowish brown colour 

 stretches a little higher. The barren fronds are always green 

 and lie in a circle upon the ground. The stalks of the fertile 

 fronds rise in the centre of those that are barren : thev are 



