176 MISSOURI BOTANICAL GARDEN. 



Two of the cases of virescence in 1909 occurred in a race 

 which I have called 0. muUiflora, the description of which 

 will be published at another time. This race is descended 

 from a single individual grown at Woods Hole in 1908. A 

 total of 376 first-generation offspring of this individual have 

 been grown in the two following years, and also (in 1910) 

 50 plants of the second generation from the self-pollination 

 of one individual of the first generation. The plants of the Fj 

 included a total of 15 virescent individuals, or very nearly4%. 

 The 50 plants of the ¥^ contained one showing virescence. 

 In a culture of 36 plants from seeds received from the Botan- 

 ical Garden at Karlsruhe under the name 0. chilensis, which 

 proved to contain two very distinct types, one plant was 

 virescent. This abnormality has not appeared in any others 

 of the many races of which I have grown cultures. 



All the plants showing virescence were affected in exactly 

 the same way, although in some the early flowers were nor- 

 mal and produced fruits, only the later flowers showing the 

 peculiarity. I have not compared the offspring from such 

 capsules with those of normal plants, though if this were 

 done it might be found that the virescent tendency was inher- 

 ited more strongly in the former case. In one plant a side 

 shoot produced flowers which were quite normal while the 

 main stem produced only flowers of the virescent type. 



One plant of 0. multiflora, in which all the flowers but 

 the earliest were virescent, is illustrated in plate 29. The 

 peculiarities of structure exhibited by these flowers may now 

 be described. Plate 30, f. 1, shows a group of the flowers, 

 natural size. The sepals are green inside and outside, large 

 and bag-like and more or less crinkled or curled. They are 

 tapering at the end, terminating in long, slender sepal tips. 

 Perhaps frondescence or phyllody would be a more suitable 

 term than virescence to apply to this condition, for the sepals 

 have become quite leaf-like. Plate 30, f. 2, shows several 

 flowers opened and photographed to show the other organs 

 of the flower. The petals retain a greenish yellow color, but 

 are in all cases very small (usually about half an inch in 

 length, though sometimes larger) and blunt at the tip. The 



