DISAPPEARANCE OF PARTS. 191 



double, in which case the wanting set is generally (but not quite 

 always) the inner, or the corolla ; 



Dichlamydeous, when both circles of the perianth (calyx and 

 corolla) are present ; 



Achlamydeous, when both are wanting, as in Fig. 365. (These 

 three terms are seldom employed.) 



Unisexual (also Diclinous or Separated) , when the suppression 

 is either of the stamens or the pistils. In contradistinction, a 

 flower which possesses both is Bisexual or Hermaphrodite. 



Staminate, or Male, when the stamens are present and the 

 pistils absent ; 



Pistillate, or female, when the pistils are present and the 

 stamens absent ; 



Monoecious (of one household), when stamens and pistils oc- 

 cupy different flowers on the same plant ; 



Dioecious (of two households), when they occupy different 

 flowers on different plants ; 



Polygamous, when the same species bears both unisexual and 

 bisexual or hermaphrodite flowers. This may occur in various 

 ways, from the greater or less abortion of either sex, either on 

 the same or on separate individual plants ; as Monceciously or 

 Diceciously Polygamous, according to the tendency to become either 

 monoecious or dioecious. Recently Darwin has well distinguished 

 the case of 



Gyno-dicecious, where the flowers on separate individuals are 

 some hermaphrodite and some female, but none male only ; and 

 Andro-dioecious, of hermaphrodite flowers and male, but no 

 separate female. The latter is a less common case. 



Neutral, as applied to a flower, denotes that both stamens and 

 pistils are wanting, a case neither rare nor inexplicable on 

 grounds of utility. (356, 504.) 



Sterile and Fertile are more loosely used terms. A sterile 

 flower may mean one which fails to produce seed, as a sterile 

 stamen denotes one which produces no good pollen, and a 

 sterile pistil one which is incapable of seeding. . But commonly a 

 sterile flower denotes a staminate one ; a fertile flower, one which 

 is pistillate, if not also hermaphrodite. 



348. Suppressed Perianth. Almost universally, when the peri- 

 anth is reduced to a single circle, it is the inner, or corolla, which 

 is not produced. Or, rather, when there is only one circle or sort 

 of perianth-leaves, it is called calyx, whatever be the appearance, 

 texture, or color, unless it can somehow be shown that an outer 

 circle is suppressed. For since the calyx is frequently delicate 

 and petal-like (in botanical language, petaloid or colored, as in 



