386 BULLETIN No. 127. [August, 



The flowers in the cultivated plants vary in color from white 

 to purple, and usually two clusters growing side by side make up 

 the compound cyme. They possess an entire, five pointed corolla 

 with five stamens with large fleshy anthers enclosing the pistil. 

 Darwin quotes Makenzie (68) as describing a variety which pro- 

 duced two sorts of flowers, the one double and sterile and the other 

 single and fertile. The sexes mature at the same time; the anth- 

 ers open at the top like a small cup, and in certain cases split for a 

 short distance. The pollen is usually wind carried, as the flowers 

 produce no nectar and are not greatly frequented by insects. Muller 

 (75 p. 425) and Fruwirth (43 v. 3 p. 6) each mention several spe- 

 cies, however, that they had noted around the flowers. Darwin 

 considered self-fertilization possible; and from the comparative 

 ease with which I have obtained "selfed" fruits in twenty-six dif- 

 ferent varieties, and from the rarity of insect visitors, I believe self- 

 fertilization to be natural to the species. The flowers open between 

 five and six o'clock a. m. in this climate and slightly close about 

 dusk. The pollen is usually shed on the second day of blooming 

 and it is then that the pistil is most receptive. With profuse seed- 

 ing varieties the flowers wither about the fourth day. 



Fraser (37 p. 5) states that out of three hundred varieties many 

 of which he has grown for several years, he has found none which 

 do not bloom at some time of their life. In opposition to this view, 

 Rev. J. R. Lawrence, of North Middleboro, Massachusetts, who 

 grows some eight hundred varieties asserts that some varieties 

 never bloom. However this may be it is certainly true that there 

 is a great variation in varieties in the power to bloom and still more 

 in their ability to set seed. Some varieties evidently go for years 

 without blooming, others bloom whenever there are optimum condi- 

 tions of climate' and season. I have found varieties setting seed 

 freely in Waupaca county, Wisconsin, when during the same season 

 plants from the same fields of the year before produced no seed 

 in Champaign county, Illinois. There are varieties which develop 

 clusters of buds which fall without opening, and many more which 

 produce flowers, all of which fall without setting fruit. Some of 

 the anthers in the latter varieties contain no pollen, others shriveled 

 pollen grains containing no protoplasm, while still others produce 

 viable pollen though never (in my experience) in large quantities. 

 The blossoms separate at certain fixed places on the stem where a 

 ring is formed by layers of tissue drying. Liebscher (66) states 

 that fragrance is correlated with yield of pollen but I have found 

 no noticeable fragrance in American varieties. 



