36 THYRSUS, ETC. [CH. 



(Fig. 12, B) as in Helianthemum, Drosera, &c. Further 

 distinctions are made according as the branches are 

 arranged in one plane or in several planes, but as the 

 terms employed have not all received general acceptance, 

 and since these complex types concern us but little, I pass 

 over further details. 



As with racemose, so with cymose inflorescences, 

 we may have them simple or compound, and the latter 

 homogeneous or heterogeneous for instance Cymes of 

 cymes are common in Caryophyllacese and Racemes 

 of cymes in Campanulaceae. The panicle-like mixed 

 inflorescence of the latter type is frequently termed a 

 Thyrsus, but there is considerable difficulty in determining 

 the details in many cases : the Horse-chestnut affords a 

 good example, however. 



Examples of cymose panicles are afforded by the 

 following : 



Horse-chestnut Vine Sumach 



Lilac Privet Tree of Heaven 



Aucuba Clematis Virginian Creeper. 



Extended research shows that there are very numerous 

 cases where racemose and cymose inflorescences pass into 

 one another, and these transitional forms go to show 

 that, in spite of the fundamental differences existing 

 between the types, practically no sharp line of demarca- 

 tion exists between the Raceme and the Cyme. For 

 instance, the raceme of the Barberry really ends in 

 a flower which, although it is the first formed and the 

 first to open, usually suffers abortion before the rest begin 

 to open, and since these latter follow the ascending order 

 we are justified in retaining for it the name of Raceme, 

 as we have done on p. 20. In the thyrsoid inflorescence 

 of the Lilac we have a similar but more complex case. 



