40 



PHARMACEUTICAL BOTANY 



axils of opposite leaves. Ctusters of this kind are seen in Catnip, 

 Horehound, Peppermint and other plants of the Labiatae. 



The raceme, corymb, umbel, etc., are frequently compounded. The 

 compound raceme, or raceme with branched pedicels, is called a panicle. 

 Ex. : Yucca and paniculate inflorescence of the oat. 



A Thyrsus is a compact panicle, of a pyramidal or oblong shape. 

 Ex. : Lilac, Grape and Rhusglabra. 



A Mdced Anthotaxy is one in which the determinate and indeter- 

 minate plans are combined, and illustrations of this are of frequent 

 occurrence. 



The order of flower development is termed ascending when, as in 



o 



N/ 



N/ 



Q 



N^ 



^/ N/ 



N/ 



F G 



Fig. 2g. — Cymose inflorescences. F, A terminal flower. G, A simple cyme, 

 compound cyme. {From Hamaker.) 



H,h 



the raceme, the blossoms open first at the lowest point on the axis and 

 continue to the Apex. Ex. : White Lily, and many other plants of the 

 same family. In the cyme the development is centrifugal, the central 

 florets opening first, while in the corymb it is centripetal, or from margin 

 to center. 



Prefloration. — By prefloration is meant the arrangement of the 

 floral envelopes in the bud. It is to the flower bud what vernation is to 

 the leaf bud, the same descriptive terms being largely employed, as 

 convolute, involute revolute, plicate, imbricate, etc. 



In addition to those already defined, the following are important. 



Valvate prefloration, in which the margins meet but do not over- 

 lap. Of this variety the induplicate has its two margins rolled inward 



