The Standard Cyclopedia of Horticulture 



A SYNOPSIS OF THE PLANT KINGDOM 



By KARL M. WIEGAND 



Most modern botanists, as well as zoologists, now think that organisms have descended, through the ages, 

 from ancestors which differed in many ways and often markedly from the present organisms, but were in general 

 of a less specialized type. It is, indeed, thought that the original life was of an exceedingly simple nature, and that 

 during the countless ages its descendents have gradually diverged from one another much as the branches of a tree 

 diverge from its trunk, until we have the enormous wealth of species and extreme diversity, and great complexity 

 of structure exhibited by the plants and animals existing today. Just as through descent in the human race we 

 have groups of individuals called families, the members of which are more closely related to each other by descent 

 than to other individuals, so we have groups of related species and genera forming similar natural families. The 

 attempt of the so-called systematic botanist of the present day is to interpret the evolutionary history of plants, 

 to discover these natural families, and to represent this knowledge of history and relationship in a synopsis of the 

 plant kingdom. Such a synopsis, therefore, attempts to show an actual "blood relationship, the real genealogy 

 of the plant kingdom. Before the theory of evolution became widely accepted as a result of Darwin's labors, 

 systems of classification were either wholly arbitrary, and planned simply for convenience in dealing with the vast 

 number of existing organisms (e.g., the sexual system of Linnaeus), or they were based on the morphological 

 relation of the flower to a certain floral plan. Since, however, the floral plan depends largely on descent, these last- 

 named systems often accidentally approached in many respects very closely to the natural systems based on 

 evolution. Instead of placing the "highest" types of plants (the most recent) last in their classification, as is now 

 done, the idealists placed them first, hence the Ranunculacea;, with" parts separate and hypogynous, and there- 

 fore most ideal, is found first in such a classification. The fusion of parts in the Compositae, and the union of parts 

 in the Gamopetalse were thought to represent a less perfect condition. Likewise, the Apetalae, with parts lacking, 

 were still less perfect, and therefore were placed later. The Gymnosperms were somewhat arbitrarily placed next, 

 followed by the Monocotyledons, in which the grasses were placed last. These in turn were followed by the ferns 

 and the lower groups. This was the system used in Bentham and Hooker's "Genera Plantarum," a great work 

 which, notwithstanding the change in system, is still a standard authority in descriptive botany. 



In the system adopted for the present synopsis, that used by Engler and Prantl in the great German work, 

 "Die Natiirlichen Pflanzenfamilien, the sequence is from the most primitive and the most ancient toward the most 

 specialized and most modern, from the lower algae to the fungi, mosses, liverworts, ferns, gymnosperms, and 

 flowering plants. Here the Monocotyledonous line culminates in the hjghly specialized Orchidaceae, and the 

 Dicotyledonous line in the equally specialized Compositae. These two families, therefore, are now thought to repre- 

 sent the present culmination of nature's handiwork in the two great lines of development in flowering plants. 



In the present synopsis of the Pteridophyta and Spermatophyta, the treatment of large groups, sequence 

 of families and family limits, is, except in a few cases, that of our most recent great work edited by Engler and 

 cited above. Among the mosses and lower plants, an abridgment of the system used in Strasburger, Noll, Schenk 

 and Karsten's "Text-Book of Botany," and other text-books, has been used. The statistics as to genera 

 and species are taken from Engler and Prantl, and are intended as general information, and may not in all cases 

 conform to the limitations as worked out by the different authors in the Cyclopedia. In some cases, particularly 

 in Cactaceae, other authorities have been followed. 



As no genera of the Thallophyta or Bryophyta are definitely treated in the body of the Cyclopedia, these two 

 groups have been introduced into the synopsis largely as a background and as a proper perspective to the plant 

 kingdom. Therefore, in these groups no divisions smaller than classes have been considered. In the Pteridophyta 

 and Spermatophyta, the plan has been to include in the synopsis every family that has at least one genus repre- 

 sented in the body of the original Cyclopedia. A few other families of minor horticultural value have found 

 place in the present Cyclopedia and are not included in this synopsis. Although the treatment in each case has 

 been of necessity reduced to great brevity, it is hoped that the condensed account of important structural char- 

 acteristics, size of family, range, and economic value will be of aid in forming a conception of what each family 

 represents. To render this conception more vivid, a list of the important cultivated genera and their common 

 names has been appended to the treatment of each family. 



The number of species in the plant kingdom is not definitely known. It has been estimated that more than 

 120,000 species of Spermatophyta and more than 60,000 species of lower plants are described. According to the 

 treatment in Engler and Prantl, these legions are classified in 640 families, of which 278 are of the higher plants 

 and 362 of plants below the Spermatophyta. The number of known species, however, is being rapidly increased 

 as research and exploration progress, so that the numbers given above are at best only approximate. The fig- 

 ures are also modified by disagreement as to what are species and what are varieties, some persons recognizing 

 more or fewer species than others in a given genus or group. 



The names of the natural families are mostly derived from the names of a leading genus (as Verbenaceae, 

 Ranunculacese) or from some marked characteristic of the group as a wh,ole (e.g., Composite, composite or com- 

 pound flowers, Cruciferse, cross-like flowers). Commonly the family name terminates in the form acex, with 

 the accent long on the antepenultimate syllable (e.g., Rosacese, pronounced Ro-saj/-si;ee) . The simple termina- 

 tion x is used mostly for subfamilies and tribes, but there are marked exceptions, as in Leguminosx. 



The illustrations accompanying this text are designed to show mainly such structural characteristics as are 

 of importance in the separation of families. For this reason, floral diagrams have been freely introduced. These 



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