DEVELOPMENT OF PLANTS 



381 



in these sporangia as already noted in the g^-mnospcrms and 

 usually but one megaspore is developed in each sporangium (Fig. 

 261^,2). 



124. Development of the Flower of Angiosperms. — The sporo- 

 phylls are variousl}^ associated in groups tliat are commonly 

 called flowers. In its simplest form, the flower may be defined 

 as a minute branch or receptacle bearing one or more sporo- 

 phylls. Such a type is illustrated in the cat- tail (Fig. 262, B, C) 



Fig. 262. Forms of primitive flowers: A, inflorescence of Typha or cat- 

 tail — mi, region bearing only flowers with microsporophylls; mg, flowers with 

 megasporophylls; h, bract. B, flower consisting of two microsporophylls 

 which are sessile on a short stalk that has numerous hairs. C, flower consist- 

 ing of one megasporophyll — s, stigma; 0, ovary surrounded with haiirs. D 

 early appearance of the inflorescence of Salix or willow. E, inflorescence 

 bearing only megasporophylls. F, flower, of a single megasporophyll with 

 forked stigma — -h, bract; n, nectar gland. G, inflorescence bearing only 

 microsporophylls. H, flower of two microsporophylls. 



where the flower consists of one or a few sporophylls associated 

 with hairs, and also in the willow where the sporophylls are 

 developed in the axil of a minute bract (Fig. 262, 7^, H). It 

 should be noted in the cat-tail that numerous spirally arranged 



