428 BOTANY. 



cence the flowers are properly lateral upon the main axis, or the sec- 

 ondary axes. The flowers develop in acropetal (centripetal) order, and 

 when the axis continues to grow the cluster may become indefinitely 

 extended, whence it is called indeterminate. In Cymose inflorescence 

 every flower is properly terminal upon a main axis or one of the sec- 

 ondary ones. In every flower cluster the main axis is first terminated 

 by a flower ; lateral branches (secondary axes) then arise at some dis- 

 tance below the apex, and each of these is terminated by a flower ; 

 lateral branches terminated by flowers arise on the secondary axes, and 

 so on. The flowers thus develop in basipetal (centrifugal) order. From 

 the fact that every axis is terminated by a flower, such clusters are 

 often called determinate. This distinction into indeterminate and deter- 

 minate is, however, a misleading one, for some botryose inflorescences 

 are in fact determinate e.g., the Umbel and Head ; while, on the other 

 hand, most of the cyrnoge flower clusters are capable of indefinite ex- 

 tension, as is notably the case witli the Helicoid and Scorpioid forms 

 It not infrequently happens that in large flower clusters a part of the 

 branching is of one type and the remainder of the other ; all such cases 

 may be considered as examples of mixed inflorescence. 



The most important of the terms in common use are given in the 

 following table of inflorescences : 



A. BOTRYOSE INFLORESCENCE. 



I. Flowers solitary in the axils of the leaves 



e.g., Vinca Solitary Axillary. 



II. Flowers in simple groups. 



1. Pedicellate. 



(a) On an elongated axis : pedicels about 



equal e.g., Mignonette Raceme. 



(6) On a shorter axis ; lower pedicels 



longer e.g., Hawthorn Corymb. 



(c) On a very short axis ; pedicels about 



equal e.g., Cherry Umbel. 



2. Sessile. 



(a) On an elongated axis e.g., Plantain.Spike. 

 Var. ft. Drooping, and scaly bracted 



e.g.. Poplar Catkin. 



Var. y. Thick and fleshy-e.gr., Indian 



Turnip Spadix. 



(6) On a very short axis e.g., Clover. . .Head- 

 Ill. Flowers in compound groups. 

 1. Regular. 



(a) Racemes in a raceme e.g.,S}nilatina.Com-pound Raceme. 



(b) Spikes in a spike e.g. , Wlieal Compound Spike. 



(r) Umbels in an umbel*./?., Parsnip.. Compound. Umbel. 



