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 ^row the cluster may become indefinitely 

 extended, whence it is called indeterminate. In Cyinose 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. Prom 

 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 cymose flower clusters are capable of indefinite ex- 

 tension, as is notably the case with 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. BOTEYOSB Inflorbscbnce. 



I. Flowers solitary in the axils of the leaves — 



e.g., Vinca Solitary Axillary. 



II. Flowers in simple groups. 



1. Pedicellate. 



(as) On an elongated axis : pedicels about 



equal — e.g., Mignonette Kaceme. 



(6) On a shorter axis ; lower pedicels 



longer — e.g., Hawthorn Corymb. 



(c) On a very short axis ; pedicels about 



equal — e.g.. Cherry XTmbel. 



2. Sessile. 



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

 Var. p. Drooping, and scaly bracted — 



e.g.. Poplar Oathin. 



Var. y. Thick and fleshy— e.g'., Indian 



Turnip Spadix. 



(J) On a very short axis — e.g.. Clover. . .Head. 



III. Flowers in compound groups. 

 1. Regular. 



(a) Racemes in a raceme — e.g"., <Simito«»a.Coiiipound Raceme. 



(6) Spikes in a spike — e.g.. Wheat Compound Spike. 



(c) Umbels in an umbel — e.g.. Parsnip.. Compound XTmbel. 



