ELEMENTS OF STRUCTURAL BOTANY. 



89 



the anther is turned towards the centre of the flower, it 

 =o said to he infrorsc; if turned outwards, ertwrsc. 



133. The cells of anthers commonly 

 open along their outer edges to dis- 

 charge their pollen (Fig. U7). In 

 most of the Heaths, however, the pol- 

 len is discharged through a minute 

 . aperture at the top of each cell (Fig. 

 *ic..47. Fig.i«. Fig.:i8. 148^^ and in our Blue Cohosh each cell 

 IS provided with a lid or valve near the top, which 

 opon3 on a kind of hinge (Fig. U9). ,. . ^ , 



'-IJ^ Stamens may be either entirely distinct from 

 each other, in which case they are described as y,- 

 droiu^, pentundrou^, oetandrou., &c.. accordinrj co then- 

 number (or, if more than twenty, as indefinite), or they 

 may be united m various ways. II their anthers are 

 united in a circle, while the filaments are separate 

 (Fi- 5':), they are said to bo s!,n,,enenoti^ ; but if the 

 filaments unite to form . tube, while the anthers remair 

 distinct, they are said to he uunuuldphous i^J-^^^^]'_'[ 

 they are in two groups they are .hrulelphor.^ (Hg. 37) , 

 if in three, tria<lelphoics : if in more than three, pohja- 



'^'135" As to insertion, when stamens are inserted on 

 the receptacle, they are lnjpn,njnons ; when borne on 

 the calyx, perupj^^n. ; when borne on the ovary, nu.y- 

 nous ■ and if inserted on tiic corolla, ep^l^talons. They 

 may ' however, be borne eve-, on the style, as in Orchis, 

 and then they are described as g,,nawlr,us, 



130 If the stamens are four in number, and in two 



r,^n- of different lengths, they are said to be dulfpu.- 



^ {V\u 58^- if six in number, four long and two 



"Z^ZyZ L*^«- (Fig. 28), .nd. fin^,, 



