DICOTYLEDONS. r-^ 



0/ / 



thcropetalae, proposed by De Candolle and Endlicher^, is now abandoned by most, 

 although still much in use for practical purposes. A. Braun" placed among the Eleu- 

 theropetalae the greater number of plants previously classed among Apetala^;* and 

 Hanstein^ has now distributed among them the remainder, so that the whole class 

 consists of only two sub-classes, Gamopetalae and Eleutheropetalse. This classifica- 

 tion however assigns far too great an importance to this particular point of structure, 

 considering that on the one hand flowers occur among the Eleutheropetalse which 

 difl'er greatly from one another not only in this but also in every other respect; while 

 on the other hand the most intimate relationship exists between particular sections of 

 Eleutheropetalce and of Gamopetalsp. I therefore think it convenient, while retaining 

 the largest sub-divisions of the class, to employ also other characters in the classifi- 

 cation ; and to make use of the character drawn from the cohesion or non-cohesion 

 of the petals in the subdivision of the largest group, that provided with two perianth- 

 whorls. In the following classification Dicotyledons are split up into five divisions of 

 equal systematic and morphological value, which should rather be arranged parallel to 

 one another than in a single linear series. This classification has also, I think, a practical 

 advantage; since the extraordinarily large number of families and orders can be more 

 easily kept in the memory when they are at once arranged in several comprehensive 

 groups of equal value. 



DICOTYLEDONS. 



Juliflorse : 



A. Piperineap, 



B. Urticinea^, 

 ('. Amentifera;, 



l^ 



MonochlamydeaB: ,^ 



A. Serpentariea-, 



x/ 



B. Rhi'/anthea-. 



ill. Aphanocycias : 



A. HydropeltidincK, 



B. Polycarpae, 



C. Cruciflorae. 



IV. Tetracyelse: 



( r J ) Ganiopetalo' : 



A. Anisocarpae, 



B. Isocarpa:. 



(/3) Eleutheropetalce : 



C. Eucycla^, 



D. Centrospermae, 



E. Discophorae. 



V. Perigynee: 



A. Calyciflorae, 



B. Corolliflorae, 



The sections designated by capital letters correspond partly to single orders, partly to 

 whole series of orders in the system referred to above. 



^ 



' Endlicher, Genera plantarum secundum ordines naturales disposila, Vindobonoe, iS.^6-1840; 

 and Enchiridion botanicum, Lipsioe — Vienna, 1841. 



•-' A. Braun, Uebeisicht des naturlichen Systems, in Ascherson's Flora der Provinz Brandenbur^S 

 1864. 



■-> Hanstein, Uebersicht des natiirlichen Pflanzensystems, Bonn 1867. In the first edition oflhis 

 book I followed this work with but little deviation. Compare also Giisebach, Grundnss der 

 systematischeu Bolanik. 



P p 



