334 HETEROMOIIPHY. 



Stackhmisia juncea, according to Clarke, has mixed 

 with its perfect flowers a number of apetalous blossoms 

 destitute of anthers.^ 



This peculiarity is well exemplified in the tribe 

 Gaudichaudieo} of the order MaJpighiacece. A. de 

 Jussieu, in his monograph, speaks of these flowers as 

 being very small, green, destitute of petals, or nearly 

 so, with a single, generally imperfect anther ; the car- 

 pels also are more or less imperfect, but not sufficiently 

 so to prevent some seeds from being formed. A similar 

 production of imperfect flowers has been noticed in 

 many other orders, e.g. Violacem^ Gampanulacece, &c. 

 In some cases these supplementary blossoms are more 

 fertile and prolific in good seeds than are the normally 

 constructed flowers. M. Durieu de Maisonneuve alludes 

 to a case where flowers of this description are produced 

 below the surface of the ground. The plant in question 

 is Scrophularia arguta, and it appears that towards the 

 end of the summer the lowest branches springing from 

 the stem bend downwards, and penetrate the soil ; the 

 branches immediately above the lowest ones also bend 

 downwards, but do not always enter the earth. These 

 branches bear fertile flowers : those which are com- 

 pletely below the soil are completely destitute of 

 petals ; those which are on the surface have a four-lobed 

 corolla, whose divisions are nearly equal, like those of 

 Veronica.^ 



To Sprengel, and specially to Darwin, physiologists 

 are indebted for the demonstration of the relation of 

 di- and trimorphic flowers to fertilisation. In certain 

 genera of orchids, such as Catasetum, &c., flowers of 

 such different form are produced that botanists, with- 

 out hesitation, considered them as belonging to different 

 genera, until the fact of their occasional production 

 on the same plant showed that they were not of even 

 specific importance. It was reserved for Mr. Darwin 

 to show experimentally that these very different flowers 



' ' A New Arrangement of Phaenog. Plants,' p. 36. 

 ' Bull. Soc. Bot. France,' 1856, t. ui, p. 569. 



