410 • BOTANICAL GAZETTE [December 



Staminate flowers 



The staminate flowers arise in short conelike catkins, consisting 

 of ipo or more flowers each, one male catkin arising beside the 

 female inflorescence near the end of the flowering shoot. Each 

 male flower consists solely of a single, elongated, inverted, pyra- 

 midal stamen with a microsporangium at each of its four corners. 



The microsporangia possess the usual epidermis, endothecium, 

 tapetum, and several-layered archesporium (figs, i, 2). From the 

 spore mother cells, tetrads of microspores are produced in the 

 usual way (figs. 3-5). The outer wall of the microspores (exine) 

 is roughened by closely packed peglike tubercles 1 /x long and 

 0.5 ju in diameter (fig. 5). There are also present over the surface 

 of the microspore 6 unthickened meridional bands, through one 

 of which the pollen tube emerges (fig. 6, polar view). The inner 

 wall of the microspore (in tine) consists of a darkly staining layer 

 of cellulose (fig. 5). The mature pollen grain has the usual vegeta- 

 tive and generative nuclei (fig. 5). 



Clarke (5) describes the stamens of the genera Chloranthus, 

 Ascarina, and Hedyosmum as being two-celled, and before opening 

 four-celled, due to a spurious, not always complete, dissepiment in 

 the line of dehiscence. He says: 



The question referring to the structure of the anthers appears to have 

 arisen entirely from those of Chloranthus itself as those of the other genera 

 [of the family Chloranthaceae] are all of the ordinary two-celled character, 

 or are spuriously four-celled from induplication at the line of dehiscence, 

 a common occurrence with two-celled anthers; and in fact the four-celled 

 structure is more apparent on a cross-section being made, both in Hedyosmum 

 and Ascarina, especially the latter. 



Neither Solms (12), Baillon (i), Eichler (6), Bentham and 

 Hooker (2), Van Tieghem (13), nor Engler (7) refer to such 

 peculiarity of structure as that mentioned by Clarke. They 

 describe the anthers as being of the ordinary four-sporangiate type. 

 The writer finds his results agreeing with the later descriptions. 

 In the sections of young anthers there are four distinct sporangia 

 present from the outset of development (fig. 1). 



Carpellate flowers 



The carpellate flowers occur in compact cymelike inflorescences, 

 several cymes in the axil of each leaf of the flowering branch. 



