33 PRACTICAL BOTANY. 



Order IV. Tetkagynia 4 styles to each flower. 



" V. Pentagynia 5 " " 



" VI. IIexagynia 6 " " 



" VII. IIeptagynia 7 " " 



« VIII. OCTOGYKIA 8 " " 



« IX. Enneagynia 9- " *' 



" X. Deoagynia 10 " " 



" XI. Dodecagynia 12 or 11 " « 



" XII. Polygynia more than 12 " 



61. The number of stamens serves to establish the 

 orders of the 16t.h, lYth, 18th, 20th, 21st and 22d classes. 

 To find their orders we proceed as follows : If a plant be- 

 longs to Monadeljplbia (XVI.), Dladelphia (XVII.), or 

 Polyadelphia, (XVIII.), we examine how many stamens 

 have gone to form the cluster, the tube, or the bundles of 

 stamens. In the class Monadelphia we have the ordei's, 

 M. Pentandria, Deeandria, and Polycmd/ria ; in Diadel- 

 phia the orders, D. Hexcmdria, Octcmdria, Deeandria / 

 and in the class Polyadelphia only one order, P. Polyan- 

 drto. 



In the class Gynandria (XX.) we meet with plants, as 

 Spiranthes, belonging to the Orchids, and Aristoloohia to 

 the Birthworts. Spiranthes has one stamen, and hence 

 belongs to Gynandria Monandria. Aristolochia, with 6 

 stamens, belongs to Gynandria Hexandria. Of the Or- 

 chids there is only one genus, belonging to the second 

 order of Gynandria ; namely, Cypripedium. 



In the classes Monoecia and Dimcia we find nearly all 



the orders represented, which are based on the number of 



stamens, and in Monoscia also the order Syngenesia, with 



the anthers united (in the Gov/rd family). 



When a plant is polygamous, we ascertain whether it is 



