ORDER OCTANDRIA. 



267 



ted scales ; these flowers have a peculiar odour, which is said 

 to produce a narcotic effect upon the brain. The use of the 

 flowers of the hop in beer are well known. This plant con- 

 tains a small portion of the nitrate of potash (saltpetre). 



HEXANDRIA, contains the honey-locust and green briar. 



OCTANDRIA, has the poplar, (POPULUS), similar in natural 

 character to the willow. Several intermediate orders occur 

 before we arrive at the 15th order MONADELPHIA ; here we 

 find the red cedar and the yew, which belong to the cone 

 bearing family, with the pine and cypress. 



We have now completed our remarks upon two classes which 

 have imperfect flowers. Our review of these has been brief, 

 when compared to the many interesting facts which presented 

 themselves in association, with the various important plants 

 which we have passed in rapid succession ; but this very mass 

 of matter has compelled us to dwell less upon particular facts. 

 We have now but one more class to investigate, in order to 

 complete our view of the Linnaean system. 



LECTURE XXXVIII. 

 CLASS XXI. CRYPTOGAMIA. 



Fig. 126. 



THE twenty preceding classes in- 

 elude the Phenogamous plants; we 

 are now to consider the Cryptogamous 

 class ; we here find the stamens and 

 pistils either wholly concealed frcyn 

 observation, or manifest only upon the 

 strictest scrutiny. These plants con- 

 stitute the first class of Jussieu, called 

 acotyledonous ; their seed being desti- 

 tute of any cotyledon. 



As we enter upon this last of the Linnasan classes, we shall 

 find all our former principles of arrangement to fail us, and it 

 might almost seem as if we had entered upon a new science. 

 The class Cryptogamia includes all plants which do not find a 

 place in some of the other classes. 



Ferns, mosses, lichens and mushrooms constitute the princi- 

 pal part of this class. At Fig. 126, a, is a fern, of the genus 



Order Hexandria Octandria Monadelphia Cryptogamia. 



