SUPPLEMENT. 



THE FAMILIES OF FLOWERING PLANTS. 



By Charles Louts Pollard. 



CHAPTER XII. 



General Characters af the Dicotyledons,' The Orders Verticlllatae and 



Plj^ercdes. 



We have now completed a somewhat hasty review of the families 

 belonging to the class of Monocotyledons. The reader must revert to 

 our discussion of the differences between this group and the Dicotyledons 

 in Chapter III, (pp. 15 and 16) of the Supplement. Dicotyledonous 

 plants vastly outnumber those of the other class, and present such 

 marked types of structure that it is necessary to group the numerous 

 orders of which they are comprised in two suhclasses, the Archichla- 

 m3'deae and the Metachlamydeae. These tremendous names have a 

 significance which will be remembered when their etymology is under- 

 stood. Both are derived from the Greek language, Archichlamydeae 

 meaning plants with a primitive floral envelope, and Metachlamydeae 

 those with a united floral envelope. The co-ordination between these 

 terms becomes more evident when we recollect that union of parts in 

 floral structure indicates, in our modern understanding, a more highly 

 advanced type. Theref)roaIl [)lants like the morning-glory, the fox- 

 glove or any composite, having a corolla composed of a single piece, 

 are considered higlier in the systematic scale than plants like the 

 buttercup, with a corolla of separate petals, or the pigweed, with no 

 corolla at all; hence the latter examples belong to the "primitive" type 

 of floral structure. It therefore follows that the Archichlamydeae 

 embrace, first, all plants having flowers without any coi'olla [Apttcdae')^ 

 and second, all plants having flowers with a corolla of separate petals 

 [Polypetcdae'). The Metachlamydeae comprise all plants having flowers 

 with a corolla united in a single piece. There are, of course, excep- 



