PREFACE. vii 



A. Corolla pol jpetalous (79-319). 



B. Corolla gamopetalous (monopetalous) . . (320-536). 



C. Incomj)lete flowers (53T-TT3). 



D. Diclinous flowers (774-903). 



E. Composites (90i-1000). 



In tlie divisions, " Corolla poljpetalous" and " Incom- 

 plete flowers," plants with poljandrous flowers will be 

 generally missed, as thej were done with in § § 6-76 ; 

 but when they are met with again, it is for good reasons. 



Whenever a genus is represented by one species only 

 (in our Flora), the specific name is given — for example, 

 Symj)locos tinctoria ; and whenever the generic name alone 

 — ^for example, LysimacfdcL — is found, it is to be under- 

 stood that the genus is represented by more species than 

 one. When species of a genus differ so widely as to be 

 equivalent to sub-genera, they will be met with in the same 

 or in separate paragraphs, as Stylisma evolvuL'des^ Choisy, 

 and Stylisma Pickering ii.^ Grray, or Phalaris aruncli- 

 nacea, and Phalaris Canarien^is^ L. 



Sometimes a genus (or a species) will be met with twice, 

 or oftener, in distant divisions. Thus, we have Peiithorum 

 sedoides in the division " Corolla j^olypetalous," as well as 

 in that of the " Incomplete flowers ;" for the flowers of this 

 species have sometimes a corolla, and oftener none. Again, 

 the calyx is sometunes furnished with an obscurely toothed 

 or obsolete limb, and the student may, therefore, look for 

 the plant among those with incomplete flowers, and lie will 

 not miss it, as the case is provided for; still he finds the 

 plant a second time among those with complete flowers. 

 Finally, a genus may be identified, although the investiga- 

 tion may be made from the apparent relations of tlie floral 

 parts, not from the true ones, as in EujpliorVia. 



