SPECIAL BOTANY 



SPECIAL Botany is concerned with the special morphology, physiology, 

 and ecology of plants. While it is the province of general botany to 

 ascertain the laws that hold for the structure, vital processes, and the 

 adaptations in the whole vegetable kingdom, it is the task of special 

 botany to deal with the separate groups of plants. It is the endeavour 

 of special morphology to obtain some insight into the PHYLOGENY OF 

 THE VEGETABLE KINGDOM by morphological comparison of the manifold 

 types of plants. The solution of this problem would provide the key 

 for the construction of a NATURAL SYSTEM of classification of plants 

 based upon their actual relationships. Such a system must necessarily 

 be very imperfect, as it is not possible to determine directly the 

 phylogenetic connection of different plants, but only to infer their 

 relationships indirectly from morphological comparisons. 



Such a natural system, founded on the actual relationship existing 

 between different plants, stands in direct opposition to the ARTIFICIAL 

 SYSTEM, to which has never been attributed more than a practical 

 value in grouping the plants in such a manner that they could easily 

 be determined and classified. Of all the earlier artificial systems, 

 the sexual system proposed by LINNAEUS in the year 1735 is the 

 only one which need be considered. 



LINNAEUS, in establishing his classification, utilised characteristics which referred 

 exclusively to the sexual organs, and on this basis distinguished twenty-four classes 

 of plants. In the last or twenty-fourth class he included all such plants as were 

 devoid of any visible sexual organs, and termed them collectively CRYPTOGAMS. 

 Of the Cryptogams there were at that time but comparatively few forms known, and 

 the complicated methods of reproduction of this large group of plants were absolutely 

 unknown. In contrast to the Cryptogams, the other twenty-three classes were dis- 

 tinguished as PHANEROGAMS or plants whose flowers with their sexual organs could 

 be easily seen. LINNAEUS divided the Phanerogams, according to the distribution 

 of the sexes in their flowers, into such as possessed hermaphrodite flowers (Classes 

 I. -XX.), and those in which the flowers were unisexual (XXI. -XXIII.). Plants 

 with hermaphrodite flowers he again divided into three groups : those with free 

 stamens (I. -XV.), which he further distinguished according to the number, mode 

 of insertion, and relative length of the stamens ; those with stamens united with 

 each other (XVI. -XIX.) ; and those in Avhich the stamens were united with the 

 pistil (XX.). Each of the twenty-four classes was similarly subdivided into 



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