THE STAMEN SYSTEM 45 



When few in number, stamens are said to be definite; when very 

 numerous, and not readily counted, they are indefinite. The follow- 

 ing terms are in common use to express their number: 

 Monandrous, for a flower with but one stamen. 

 DiANDROUS, with two stamens. 

 Triandrous, with three. 

 Tetrandrous, with four. 

 Pentandrous, having five. 

 Hexandrous, six. 



POLYANDROUS, an indefinite number. 

 As to insertion, they are: 

 Hypogynous, situated on the receptacle. 

 Perigynous, on the calyx tube or disc. 

 Epigynous, on the top of the ovary. 

 Gynandrous, borne upon the pistil, as in the Orchids. 

 The stamens may be of equal length; unequal, or of different length. 

 Didynamous, when there are two pairs, one longer than the other. 

 Tetradynamous, three pairs, two of the same length, the third 

 shorter. 



Terms denoting connection between stamens are: 

 MoNADELPHOUS (in One brotherhood), coalescence of the filaments 

 into a tube. 



DiADELPHOtrs (in two brotherhoods), coalescence into two sets. 

 Triadelphous, with filaments united into three sets. 

 Polyadelphous, when the sets are numerous. 

 Syngenesious, when the anthers cohere. 



Stamens may be erect, extending directly upward, spreading, pro- 

 ceeding upward and outward; connivent brought close together and 

 turned inward; reflexed, turned downward. 



The attachment of the anther to the filament may be in one of sev- 

 eral ways, as follows: 



Innate, attached at its base to the apex of the filament. 

 Adnate, adherent throughout its length. 



Versatile, when the anther is attached near its center to the top 

 of the filament, so that it swings freely. The adnate and versatile are 

 INTRORSE when they face inward, extrorse when they face outward. 

 In order that the pollen may be discharged at the proper time, the 

 anther opens along a line or suture called the line of dehiscence, either 

 longitudinal or transverse, or the pollen escapes through apical or val- 



