APPENDIX ON THE CLASSIFICATION OF 

 PLANTS. 



BY M. 0. POTTER. 



THE earliest systems of classification were derived from the 

 properties and uses of plants ; and it was not until some two 

 centuries ago that any scientific grouping of plants was attempted. 

 Aristotle and Theophrastus had adopted the groups of Trees, 

 Shrubs and Herbs as the chief divisions of the Vegetable King- 

 dom, a system which persisted and was employed by Tournefort 

 and Ray as late as the end of the 17th century. The arrange- 

 ment by which these three divisions were separated into smaller 

 divisions was often founded upon a single character, such as the 

 formation of the corolla, the form of fruit, that of the calyx and 

 corolla, etc. All these systems of classification which brought 

 into close proximity plants distinguished by some one character 

 alone, could only be considered as artificial, since plants related to 

 one another would not necessarily be included in the same group. 

 As the knowledge of the morphology, physiology, and reproduction 

 of plants increased, such systems were recognised as unscientific, 

 and it became the aim of botanists to establish a natural system, 

 founded upon mutual relationships, which would associate together 

 only those plants which are truly allied. 



The following are some of the chief systems of classification 

 which will show the gradual development of the natural system, 

 and may be of service to students making use of this text-book. 1 



System of JOHN RAY (1703). 

 I. Herbse. 



A. IMPERFECTS (Flowerless) 



B. PERFECTS (Flowering). 



Dicotyledones. 

 Monocotyledones. 

 II. Arbores. 



A. Monocotyledones. 



B. Dicotyledones. 



Ray was the first botanist who recognised the importance of the 

 one or two seed-leaves of the embryo, and initiated the division of 

 the Flowering-plants into Monocotyledons and Dicotyledons. 



1 For further reference see Sachs, History of Botany; Lindley, Vegetable 

 Kinydom; Le Maout and Decaisne, General System of Botany, etc. 



576 

 W. B. P P 



