16. ASEXUAL REPRODUCTIVE ORGANS 55 



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

 tifolia). 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 hypsophylls (see p. 43). 



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, bear- 

 ing one or more sporangia or sporophylls, is termed & flower (p. 25). 



When hyposophylls 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 occa- 

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

 the flower and produces foliage-leaves ; this is termed prolifera- 

 tion. 



When the rhachis bears a single terminal flower it is commonly termed 

 the peduncle of the flower ; when the rhachis is branched, the branches may 

 be so short that their flowers appear to spring directly from the rhachis 

 and the flowers are said to be sessile; when the branches are longer 

 and bear terminal flowers, they are termed pedicels, and the flowers 

 are said to be pedicillate. For further details as to inflorescences, see 

 Part IV. 



When no sporophylls are present, the form of the flower is ex- 

 tremely simple. When sporophylls are present, the form of the 

 flower varies with the degree of elongation attained by the termi- 

 nal internodes of the axis. When they elongate to some extent, 

 the flower forms a cone, as in Equisetum, Lycopodium, Selaginella, 

 Pinus. When they remain short, as generally in Angiosperms, 

 the apex is more or less broadened, forming a flattened, depressed, 

 or shortly conical torus on which the sporophylls and the perianth- 

 leaves are borne. The various forms of flowers are described in 

 detail in Part IV. 



