88 TORREYA 



been working recently, causes increased growth in flowers. It depresses growth 

 in the plant as a whole but stimulates rate of growth in flowers. In a number 

 of different plants to which it has been taken, it causes the production of giant 

 blossoms. Its action on tomato flowers is shown in figure 1. In the truss ou 

 the left the flowers are normal, while in the other two they are diseased. Tht 

 sepals of the diseased flowers are much larger than sepals of normal flowers. 

 Instead of remaining separate as in healthy blossoms, the affected sepals have 

 fused to form a sac-shaped structure. When the sac w^as torn open, it was 

 found that the petals were green in coloV and borne at the end of a thick stalk 

 which was about an inch in length. The petals were leaf -like in structure ; some 



Fig. 1. False blossom in tomato. The flowering truss at the left is healthy; the other 

 two are diseased. (Photograph by J. A. Carlile.) 



were simple and others compound. The anthers were usually small and green. 

 In its eft'ects on tomato flowers, false blossom resembles the big-bud disease 

 which occurs in the western part of this country (1) and in Australia (11). 

 Other effects of false blossom on flower trusses are shown in figures 2 and 3. 

 The diseased truss pictured in figure 2 was about four times as long as the 

 healthy truss. It terminated in two stem tips bearing leaves. The stem of the 

 diseased truss also was thicker than that of the healthy truss. Figure 3 shows 

 other variations in the deformation of enlarged flower trusses. 



Some diseased trusses that had not elongated so much but were borne on 

 thick stems are displayed in figure 4 beside a normal truss. This type of mal- 

 formation was met with less often than the big-bud type. Apparently there are 

 several different strains of false blossom virus prevalent in nature. From some 

 diseased cranberry plants a strain was obtained that caused a severe check to 

 longitudinal growth but stimulated transverse growth. Plants with this strain 

 stopped producing flower buds soon after they were infected and did not stimu- 

 late the production of secondary shoots. From other false blossom cranberry 



