ABRIDGED 
ARBORETUM ET FRUTICETUM 
BRITANNICUM. 
Trees and shrubs, in common with all other flowering plants, are arranged 
by botanists in two grand divisions ; viz. the Exogenous, or Dicotyledonous, 
Plants, the stems of which increase from without, and the leaves of which 
have reticulated veins ; and the Endogenous, or Monocotyledonous, Plants, 
the stems of which increase from within, and the leaves of which have parallel 
veins. The first class includes all the hardy trees and shrubs in Britain, with 
the exception of shrubs of the genera Yucca, Smilax, Riscus, and one or two 
others, which belong to the second class. We shall arrange the genera and 
species under the same subdivisions, subclasses, sections, orders, and tribes, 
as we have adopted from DeCandolle in our Hortus Britannicus. 
Cuass I. EXO’/GENZE. 
Stems increasing from without ; Leaves with reticulated Veins, 
Susppivision I. DICHLAMY’DE. 
Calyx and Corolla distinct, by which they are distinguished from Subdivision 11, 
in which the flowers have only a calyx. 
It is inconsequence of this high developement of the floral envelopes, that 
the greater part of handsome-flowering trees and shrubs are found in Dichla- 
mydez, it rarely happening that those with a single floral envelope have any 
brilliant colouring. 
Susciass I. THALAMIFLO‘'R/. 
Flowers with Petals and Stamens inserted in the Receptacle 
This subclass contains all the Polyandrous plants of Linnzus ; as the sub- 
class Calyciflére, in which the stamens are seated on the calyx, contains all 
the plants of the Linnzan class Icosandria. 
Section I. 
’ Carpella, that is, the component Parts of compound Capsules or Fruits, numerous; 
or the Stamens placed opposite the Petals. 
Orper I. RANUNCULA‘CEZ. 
THE Diagnostic, or Distinctive, Character, or, a8 we shall term it, the Ordinal 
Character, of this order, is thus given by Dr. Lindley :— “ Polypetalous, 
B « 
