NATURAL ARRANGEMENT 



OP THE 



GROUPS AND ORDERS IN THIS WORK. 



THE VEGETABLE KINGDOM is arranged, by Prof. A. GRAY in his Botanical Text 

 Book (which arrangement is here adopted), in two Series or grand Divisions 

 known as Phaenogamous or Flowering Plants, and Cryptugamous or Flowerless 

 Plants. These, again, are subdivided ; and the plants belonging to them are 

 disposed, according to their structure and affinities, in Classes, Sub-Glasses, Divisions 

 Groups, Orders, Sub-Orders, Tribes, Sub-Tribes, Genera, Sub-Genera, Species and 

 Varieties. 



The following is a Synoptical View of the general arrangement and grouping of 

 the Natural Orders, or Families, to which the plants enumerated in this work are 

 referable ; which, the intelligent reader will perceive, has been derived from the 

 valuable Text-book, above mentioned. Such a Conspectus, it is believed, may be 

 satisfactory and useful to the Student, as affording a comprehensive glance at 

 the general principles, or basis of the System, upon which the superstructure of 

 details has been erected. Under this impression it has been here inserted. 



SERIES I. 



PHAENOG'AMOUS OR FLOWERING 

 PLANTS. 



PLANTS furnished with flowers (essentially consisting of stamens 

 and pistils], and producing proper seeds. 



CLASS I. 



EXOGENOUS OR DICOTYLEDONOUS 

 PLANTS. 



STEM consisting of a distinct bark and pith, which are separated 

 by an interposed layer of woody fibre and vessels, forming wood in 

 all perennial stems ; increase in diameter effected by the annual 

 deposition of new layers between the old wood and the bark, which 

 are arranged in concentric zones, and traversed by medullary rays. 

 Leaves commonly articulated with the stem, their veins branching 

 and reticulated. Sepals and petals, when present, more commonly 

 in fives or fours, and very rarely in threes. Embryo with two or 

 more cotyledons. 



