228 THE STRUCTURE OF FLOWERS. 



Caltlia palustris is said to be androdioecious, but no 

 details are given by the observer.* 



Besides the UmbelUfer(B,'\ where andromonoecism seems 

 to be a characteristic feature, Miiller mentions Asperula 

 taurina and Galium Gruciata, Fulmonaria officinalis, Goriaria 

 7yiyrtifolia,eiJid Diospyrus Virginiana as being andromonoecious. 

 The hermaphrodite flowers of these species are protandrous. 



In Galium Gruciata, Mr. Darwin noticed that the pistil is 

 suppressed in most of the lower flowers, the upper remaining 

 hermaphrodite. 



Heterostylism may tend to produce the same result when 

 the stamens of the long-styled forms degenerate so far as to 

 become atrophied without the pistil losing its functions. 

 Fulmonaria angustifolia and Phlox siibulafa give hints of this 

 condition.;]: Asperula scoparia was at first thought by Mr. 

 Darwin to be heterostyled, but finding the anthers to be des- 

 titute of pollen, he considered it to be dioecious. A. taurina, as 

 figured by Mu]ler,§ shows great variability in the lengths of 

 the filaments and styles, and he pronounces it to be andro- 

 monoecious. Hence, as so many of the Buhiacece are hetero- 

 styled, there seems eYery probability of one result of this 

 peculiarity, being one or other kind of this incompletely 

 afl'ected or partial diclinism. In the case of Goriaria myrti- 

 folia, Hildebrand found that it was the first flowers which 

 were male only. In Maples, as in Galium Gruciata, the rule is 

 for the three or more flowered corymb to have the central 

 one hermaphrodite, and the lower or outer ones male. This 



* Lecoq, Geog. Bot., torn, iv., p. 488. 



t Miiller says that in Sanicula Europcea the outer flowers are male, 

 and develop after the inner ones, which are hermaphrodite. This is so 

 anomalous, that one suspects an error somewhere. I ha^e not had any 

 opportunity of examining fresh flowers. 



X Forms of Flowers, p. 287. 



§ Fertilisation, etc., p. 303. 



