76 PART I. THE MORPHOLOGY OF PLANTS. [ 16. 



as the inflorescence, but there is no reason for confining the use of 

 this term to this group of plants. The sporophore or inflorescence 

 is characterised by its limited growth in length, and can usually 

 be distinguished from a vegetative shoot by peculiarities of form, 

 and, when they are present, by the nature of its leaves. 



The distinction of an inflorescence from a vegetative shoot is easy when the 

 former is an entire branch borne laterally on the latter ; but when a monopo- 

 dial vegetative shoot terminates in an inflorescence, the transition from the 

 one region to the other is so gradual, that it is difficult to determine where the 

 one begins and the other ends. 



The sporophore may be simple, or it may be branched, and it then 

 affords some of the most striking examples of the various branch- 

 systems (see p. 32). When the branch-system is such that there 

 is a well-defined main axis, this is termed the rhachis of the inflo- 

 rescence. The rhachis and the branches of the inflorescence are 

 commonly elongated and cylindrical, or flattened, or prismatic in 

 form ; but they are in many cases dilated at the apex into a flat- 

 tened, depressed or conical receptacle, as in the Compositse, etc. 



The sporophore may be destitute of leaves (e.g. Salisburia adian- 

 t! folia). When it bears leaves they usually differ more or less 

 widely in form, colour, and structure from the foliage-leaves of 

 the plant. Of these leaves there are two kinds : those which bear 

 sporangia, hence termed sporophylls ; those which do not bear spo- 

 rangia, termed hypsopJiylls (see p. 59). 



When no sporophylls are present, the sporangia are borne 

 directly by the rhachis or the branches of the sporophore, at or 

 near the apex, in a cluster if there are several. When sporo- 

 phylls are present, they are also usually collected together at the 

 apex of the rhachis or of a branch, in consequence of the short- 

 ness of the terminal internodes. Any axis of the sporophore, 

 bearing one or more sporangia or sporophylls, is termed ^floicer. 



When hypsophylls are present, some of them are commonly 

 aggregated round the sporangia or the sporophylls, as in most 

 Angiosperms, constituting what is termed the perianth of the 

 flower. 



When the rhachis is unbranched, it bears a single terminal 

 flower (e.g. Equisetum, Violet) ; when it branches, each axis, of 

 whatever order, terminates in a flower. It is on this account that 

 the growth of the axes of inflorescences is limited. It occasion- 

 ally happens, as a monstrosity, that the axis grows through the 

 flower and produces foliage-leaves ; this is termed proliferation. 



