f 



THE DEHISCENCE OF ANTHERS BY APICAL PORES. 175 



paratively, their essential points of difference may be 

 stated. 



The Ericaceous type as limited in this paper contains 

 some forms which are closely related to those of the three 

 following, but they will be left out of consideration here. 



The Dilleniaceous, Solanum -Cassia and Melastomataceous 

 types have in common a widely patent corolla, or at least 

 a widely expanded corolla limb, and elongate, usually 

 linear, basifixed anthers. The Dilleniaceous type differs 

 from the other two in the possession of a larger number of 

 stamens, with anthers inserted on generally long filaments, 

 and often separate styles. The Solanum-Cassia type 

 differs from the Dilleniaceous in the number of stamens, 

 their much reduced filaments, and their frequent approxi- 

 mation around the style. The Melastomataceous type is 

 characterized by anthers of the same general form as those 

 of the Solanum-Cassia type, but it is sharply separated by 

 the elongate and highly differentiated filament. 



I. ARACEOUS TYPE. 



Flowers usually densely crowded on a spadix ; perianth 

 generally much reduced; filaments usually shortened; 

 anthers free or very often connate in a synandrium, biloc- 

 ular or multilocellate, each locule dehiscing by a more or 

 less irregular apical rent, or in a few cases, through a pro- 

 duced tubular process; pollen free or conglomerate in a 



vermiform column. 



To this type belong many of the genera of the Araceae 

 and Balanophoraceae. Other genera of these families shed 

 their pollen through longitudinal slits in the usual way. 



The Loranthaceae and Lacistemaceae furnish interesting 

 forms for comparison. 



The geographical distribution and the floral ecology of 

 this type will not be discussed here. It is clearly distinct 

 from others to be treated later and to which I wish to 



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direct especial attention. 





