﻿VIRESCENCE OF OXALIS STRICTA. 



105 



The flowers of normal 0. stricta open widely on bright morn- 

 ings and close at noon. The flowers of 0. stricta viridiflora 

 never open widely, but on the other hand are but little influ- 

 enced by the amount of light. They open in the morning 

 and never close, something very different from what happens 

 in 0. stricta. Here the petals close over the young fruit, and 

 sooner or later become loosened at the base. Frequently 

 they form a cap which is carried up on the tip of the growing 

 fruit, where they may remain till maturity. In the variety 

 viridiflora, however, the petals persist, in good condition, 

 for a long time, often till the fruit is nearly ripe (plate 11). 

 This agrees with the observations of others in similar cases.* 



The fertility of the variety does not appear to have been 

 impaired, since both in 1906 and 1907 seed could be gathered 

 in large quantities. It is absolutely self-fertile, as will be 

 shown later. An attempt to distinguish plants by relative 

 lengths of stamens and styles yielded no satisfactory results. 



When the plants of Oxalis stricta viridiflora were met with 

 for the first time, it was thought that the green color of the 

 petals was due merely to a passing virescence and that the 

 green-petaled strain might perhaps be propagated in a vege- 

 tative manner. This, experience has shown us to be possible 

 for frondescence not caused by parasitcsf such as is met with 

 in the green rose and wheat-ear carnation. For this reason, 

 in September, 1906, a few plants of the variety were trans- 

 ported to the Missouri Botanical Garden, where they were 

 kept in pots in a cold frame over winter. The attempt met 

 with but indifferent success. During October and November 

 a few small, green-petaled flowers made their appearance. 

 In the spring the single small plant which survived was trans- 

 planted to a frame and there produced a few flowers, all green. 

 At no time was there material for purposes of vegetative 

 propagation, and finally the plant died. 



This was no great loss, since it was found that in the spring 

 of 1907 a number of green-flowered specimens had again ap- 



* Masters, M. T. Vegetable Teratology. 241. 



t De Vries, Hugo. Eeu epidemie van vergroeningen. (Botanisch 

 Jaarboek. 8 : 66. 1896). 



