118 MOEPHOLOGT, OR COMPAEAT1YE ANATOMY. 



condition, analogous to that in the Amentiferous Dicotyledons, and in 

 some cases is abortive. In Scirpus (fig. 220) it consists of a circle of 

 bristles ; in Eriophorum it is a tuft of hairs, which grow out into a " lock " 

 of cotton as the fruit ripens. In Carex (fig. 221) there is an urceolate or 



Fig. 220. 



Fig. 221. 

 b 



Fig. 220. Flower of Scirpus, the essential organs surrounded by a circle of bristles. 

 Fig. 221. Female flower of Carex: a, the perigynium, or perianth, in the axil of a bract; 

 b, the tubular perigynium cut open vertically, to show how it surrounds the pistil. 



inflated tubular perigynium or ictriculus surrounding the pistil of the 

 fertile or female flower, which stands in the axil of a bract, and which is 

 itself composed of the union of two scales or bracteoles. Cyperus, Cla- 

 dium, &c. have the essential organs naked in the axil of a bract. 



Sect. 9. THE ESSENTIAL ORGANS OF FLOWERS. 



The essential organs of flowers consist of an androecium or as- 

 semblage of stamens, and of a gyncecium or pistil consisting of carpels 

 with their contained ovules. The androecium and the gynsecium 

 are both present in perfect flowers, although these latter may be 

 incomplete, from the absence of floral envelopes. In diclinous or 

 unisexual flowers the stamens or pistils exist alone, and the flowers 

 are consequently imperfect. 



Organs morphologically intermediate between petals and stamens occur, 

 not only normally, as in the flowers of Nymphaa, but such structures are 

 very common in monstrous double flowers, bearing anthers or polliniferous 

 lobes upon the borders of petals. The morphological connexion is also 

 kept up by the existence of sterile filaments or stamen-stalks, w r hich, like 

 the filaments of perfect stamens, may exhibit a petaloid character. 



In monstrous flowers sometimes imperfect organs present themselves, 

 partaking of the outward characters both of stamens and carpels. 



The Disk. Abortive organs, referable either to the corolline or the 

 staminal circles or excrescences therefrom, have been already referred to ; 

 but it is desirable to notice more particularly the conditions of those struc- 

 tures which are commonly described under the name of disk (see p. 100). 



