Chap. IV. OXALIS, HOMOSTYLED SPECIES. 181 



propagated asexually. It is probable that this kind 

 of propagation would be much aided by there being 

 no expenditure in the production of seed. 



Oxalis (Biophytum) sensitiva. — Tliis plant is ranked 

 by many botanists as a distinct genus. Mr. Thwaites 

 sent me a number of flowers preserved in spirits from 

 Ceylon, and they are clearly trimorphic. The style 

 of the long-styled form is clothed with many scattered 

 hairs, both simple and glandular ; such hairs are much 

 fewer on the style of the mid-styled, and quite ab- 

 sent from that of the short-styled form ; so that this 

 plant resembles in this respect 0. Valdiviana and 

 Regnelli. Calling the length of the two lobes of 

 the stigma of the long-styled form 100, that of 

 the mid-styled is 141, and that of the short-styled 

 164. In all other cases, in which the stigma in this 

 genus differs in size in the three forms, the differ- 

 ence is of a reversed nature, the stigma of the long- 

 styled being the largest, and that of the short-styled 

 the smallest. The diameter of the pollen-grains from 

 the longest stamens being represented by 100, those 

 from the mid-length stamens are 91, and those from 

 the shortest stamens S-t in diameter. This plant is 

 remarkable, as we shall see in the last chapter of 

 this volume, by producing long-styled, mid-styled, 

 and short-styled cleistogamic flowers. 



Homostyled Species of Oxalis. — Although the majorit)' 

 of the species in the large genus Oxalis seem to be 

 trimorphic, some are homostyled, that is, exist under 

 a single form ; for instance the common 0. aceio- 

 SfUa, and according to Hildebrand two other widely 

 distributed European species, 0. stricta and corniculata. 

 Fritz Miiller also informs me that a similarly consti- 

 tuted species is found in St. Catharina, and that it is 



