438 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 Cyniose 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) tlien 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 pn. 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 bolryose 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 tlie other ; all such cases 

 may be considered as examples of mixed inflirescence. 



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

 following table of inflorescences : 



A. BoTRYOSB Inflorbscbncb. 



I. Flowers solitary in the axils of the leaves — 



e.g., Vinea Solitary Axillary. 



II. Flowers in simple groups. 



1. Pedicellate. 



(a) On an elongated axis : pedicels about 



equal — e.g.. Mignonette IRaceine. 



(6) On a shorter axis ; lower pedicels 



longer — e.g., Hawthorn Corymb. 



, (c) On a very short axis ; pedicels about 



equal — e.g., Cheery.' ; ..'. Umbel. 



2. Sessile. 



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

 Var. /3. Drooping, and scaly bracted — 



e.g.. Poplar , GatUn. 



y&T.y. Thicka.nd&eshy— e.g., Indian 



Turnip Spadix. 



(6) On a very siiort axis — e.g.. Clover. . .Head. 



III. Flowers in compound groups. 

 1. Retrular. 



<a) Racemes in a raceme — e.g., 8mila,eina.Com.-povin6L Baceme. 



(6) Spikes in a spike— «.ff.. Wheat Compound Spike. 



(c) Umbi'lg in an umbel— e..?., Par»«i^.. Compound Umbel, 



