MORPHOLOGY OF EEPEODUCTIVE OEGANS 



The SporopJiore or Inflorescence. 



In the sporophytes of all the higher plants, the sporangia, 

 and the sporophylls on which they arise, are collected together 

 to a greater or less extent, and thus give rise to peculiar modi- 

 fications of the ordinary vegetative body. In the so-called 

 Flowering Plants, or Phanerogams, the sporophylls with their 

 sporangia occur in special structures known as flowers. These 

 in turn are usually arranged upon special branches, which form 

 a branch system, sharply marked off from the remainder of the 

 plant. This branch system constitutes what is generally called 

 the sporophore or inflorescence. In many of the lower plants 

 the inflorescence is not so conspicuously shown, the sporophylls 

 often resembling the foliage leaves and not being collected into 

 flowers. The terva flower should not, however, be restricted to 

 the so-called Flowering Plants, but may be applied to any shoot 

 especially adapted to spore -production. The flower of the Phane- 

 rogams consists of an axis, generally bearing leaves, which may 

 be of two kinds : the sporophylls, or those which carry the spo- 

 rangia, and certain protective leaves which bear the name of the 

 perianth. Sometimes the axis bears no leaves, and the sporangia 

 are developed upon the axis itself, as in the female flower of the 

 Yew-tree. Usually in Phanerogams the flower includes two 

 kinds of sporophylls : those bearing microsporangia, which are 

 named stamens ; and those carrying megasporangia, which are 

 known as carpels. Many flowers, however, only contain one of 

 the two, and are then known as siaminate and ■pistillate respec- 

 tively. 



The sporophyll may present many forms : in most Ferns it 

 can only be distinguished from an ordinary foliage leaf by the 

 presence of the sporangia on its under surface ; in the Equi- 

 setums, or Horsetails, it is a peltate scale ; several spring 

 together from the apex of the shoot, each bearing many sporangia 

 between the scale and the axis ; in most Gymnosperms the 

 form varies from a structure similar to that of Equisetum, to 

 a broad-based, scaly leaf, with the sporangia either on its 

 dorsal (male flower of Pinus) or ventral surface (female flower 

 of the same plant). In the Angiosperms the stamen is a club- 

 shaped body with a swollen head ; the carpel is more leaf-like, 

 appearing in its most typical form miich like a leaf folded upon 

 its midrib, and having its margins united in front as in Ranun- 

 culus. The closed chamber so formed is known as the ovary. 



