1917] Bergman,—Abnormal Flower Structure in Oxalis stricta 43 
normal flowers the pistil is columnar, sharply 5-angled and measuring 
usually 16-18 mm. in length. In most of the variant forms examined 
the pistil was much smaller than in normal flowers and in many speci- 
mens more or less twisted and distorted. The smaller pistils were 
obpyriform in shape, with the lobes or divisions usually strongly 
rounded on the back and only in a very few specimens sharply angled 
as in normal flowers. Development of seeds in any abnormal speci- 
mens was not observed. 
Most of the specimens found were of the kind shown in figures 7, 
8 and 9. These flowers were the nearest approach to the usual type. 
The sepals were broadly ovate and leaf-like. The petals differed 
only in being narrower, shorter and very pale in color, The stamens 
differed from normal ones in being separate. The anthers of the outer 
series were apparently normal while those of the inner series were 
poorly developed or entirely lacking. The smallest flower measured 
only 3 mm. in diameter with a pistil less than 1 mm. in height. Most 
of the smaller flowers (fig. 9) measured 5-6 mm. in diameter with 
pistils 1.5-2 mm. in height. The larger forms measured 7-8 mm. in 
diameter with pistil about 4 mm. high. A few specimens had sharply 
angled pistils (fig. 7), thus resembling most nearly the form of the 
pistil in normal flowers. The pistil of the specimen shown in figure 9 
was obpyriform and sharply angled, in these respects being inter- 
mediate between the specimens shown in figures 7 and 8, but smaller 
than either of them. $ 
Two flowers (figs. 10 and 11) had enlarged, obpyriform or balloon- 
shaped pistils, the carpels being partly separate at the apex so that 
the interior of the ovary could be observed. No ovules were present 
in these specimens. The sepals and stamens of these flowers were as 
above described. The petals were rather longer than in most speci- 
mens and narrowly obcuneate. 
A more extreme variation in the pistil form was observed in several 
flowers (figs. 12, 13 and 15). In these the carpels appeared as sepa- 
rate parts, outspread so as to resemble the petals of a flower. This 
condition might be produced from a form such as is shown in figures 
10 and 11 by having the carpellary leaves become separated to the 
base and changed from a vertical to a horizontal position. Inside the 
carpellary leaves are small leaf-like structures which apparently re- 
place the ovules of a normal ovary. 
The specimens shown in figures 14 and 16 were the most interesting 
