DISAPPEARANCE OF PARTS. 



193 



trimerous) flowers of Saururus, Fig. 365. But achlamydeous 

 blossoms are usually still further reduced to a single sex. 



352. Suppression of one circle of stamens is of very common 

 occurrence. It is seen in different species of Flax ; which have 

 mostly 5-merous perfectly symmetrical and complete flowers with 

 one set of stamens abortive. In some species (as in Fig. 3G7), 



367 



vestiges of the missing circle of stamens are conspicuous in 

 the form of abortive filaments, interposed between the perfect 

 stamens ; in others, these rudiments are inconspicuous or even 

 altogether wanting. 



353. Suppressed Androecium or Gynoecinm. This occurs with- 

 out or along with suppression in the perianth. In cases of the 

 former, vestiges of s;o sn 



the aborted organs 

 often remain to sig- 

 nify the exact nature 

 of the loss. Sepa- 

 ration of the sexes 

 (monoecious, dioeci- 

 ous, &c.) is the re- 

 sult of sueh suppres- 

 sion. In Menisper- 

 mum (Fig. 368, 369), 

 this is accompanied 

 by an actual doub- 

 ling of both calyx 

 and corolla. The 

 dioecious flowers of 

 Sinilax are similarly 

 complete, except by 

 the abortion of one sex, but the calyx and corolla are single. 



FIG. 366. Flower of a Linum or Flax. 367. Andraecium and gyncecium ; the former 

 of 5 perfect stamens, alternating with 5 rudiments of a second set. 



FIG. 368, 369. Dioecious flowers of Moonseed, Menispermum Canadense : 368, Stami- 

 nate or male blossom; 369, Pistillate or female, but with six abortive stamens, before 

 as many petals. 



FIG. 370. A catkin of staminate flowers of a Willow, Salix alba. 371. A single 

 staminate flower detached and enlarged (the bract turned from the eye). 372. A pistil- 

 late catkin of the same species. 373. A detached pistillate flower, magnified. 



