EXOGENOUS OK DICOTYLEDONOUS PLANTS. 375 



Series I. Flowering ok Ph^nogamous Plants. 



Plants furnished with flowers (essentially consisting of stamens 

 and pistils), and producing proper seeds. 



Class I. Exogenous ok 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 stems, 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 

 rarely more) cotyledons. 



Subclass 1. Angiospekmous Exogenous Plants. 

 Ovules produced in a closed ovary, and fertilized by the action of 

 pollen through the medium of a stigma. Embryo with a pair of op- 

 posite cotyledons. (For convenience, the very numerous orders of 

 this subclass are divided into those with polypetalous, monopetalous, 

 and apetalous flowers. This holds in a general way ; but a good 

 many genera and species of mainly polypetalous, and some of mono- 

 petalous orders, are apetalous. The character of the following divis- 

 ion must therefore be regarded as liable to exception in this respect. 

 For example, many of the genera of the first order have apetalous 

 flowers. — The earlier groups of this division are mostly hypogy- 

 nous ; those that succeed, perigynous ; the last are epigynous.) 



Division I. Polypetalous Exogenous Plants. 

 Calyx and corolla both present ; and the petals distinct. 



Conspectus of the Okders. 



Group 1. Ovaries several or numerous (in a few cases solitary), distinct, when 

 in several rows sometimes cohering in a mass, but not united into a com- 

 pound pistil. Petals and stamens hypogynous. Seeds albuminous. 

 * Stamens or pistils (one or both) numerous or indefinite. 



Herbs without stipules. Banuncclaoe^. 



Shrubs or trees. Corolla imbricated in the bud. Magnoliace^. 



Shrubs or trees. Corolla valvate in the bud. Anonace^e. 



