SOME NOTES ON THE POLLINATION OF FLOWERS, 
BY S. GRAENICHER. 
JEFFERSONIA DII'IIYLLA (£.) PERS. AND SANGUINARIA CANA- 
DENSIS L. 
The flowers of the twin-leaf (J cffcrsonia diphylla) and blood- 
root {Sanguinaria Canadensis) are among the most conspicuous 
of our early flowers of spring. Although representing two quite 
distinct families, these flowers have from an ecological point of 
view several features in common, and for the sake of comparison 
they are considered together. Sanguinaria is a rather frequent 
plant in our region, while of Jeffersonia it must be stated with 
regret that it is gradualy disappearing from the immediate sur- 
roundings of Milwaukee. The observations recorded below were 
made on the southwestern slope of a hill in the Menomonee 
Valley between Milwaukee and Wauwatosa. In this particular 
locality the two plants occur close together, the flowers of the 
bloodroot always appearing two or more days in advance of those 
of the twin-leaf. In size and general appearance these two flowers 
resemble each other to such an extent that they are not easily dis- 
tinguished at a distance. Both are typical pollen-flowers, not a 
trace of nectar being produced by either of them. 
JEFFERSONIA DIPHYLLA (l.) PKRS. TWIN-I/EAF. 
Altogether two species of Jeffersonia are known, one from 
Manchuria in Eastern Asia, and the other from the eastern part 
of North America. Nothing has been reported so far concerning 
the pollination of either of them. 
The earliest flowers of our species, /. diphylla, make their 
appearance as a rule during the fourth week in April. In 1900, 
for example, the flowering season extended from April 26 to 
May 13. The solitary white flower has a diameter of 4 to 4^ 
cm., and is situated at the end of an erect scape about 2 dm. in 
length. The sepals fall off very early, mostly before the spreading 
of the 8 petals. The latter are about 2 cm. long and pure white, 
while the sepals and scape have a purplish tint. In the newly 
opened flower the 8 stamens are directed away from the pistil. 
They have a length of 11 mm., 8 mm. of which are to be credited 
to the anthers. The pistil is equally as long as the stamens, and 
carries a flattened stigma on top of a short style. 
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