4 BULLETIN 542, U. S. DEPARTMENT OF AGRICULTURE. 



ovary 1 millimeter broad, with a slender lateral style about 2 milli- 

 meters high. To one side and inserted upon the disk is the single 

 fertile stamen, composed of a slender subulate filament about 1.5 

 millimeters long, surmounted by an oval, purplish red anther 0.5 

 millimeter long, which dehisces longitudinally. (PL II.) Occasion- 

 ally two such stamens are produced. The whorl is completed by 

 staminodes of varying prominence, short and subulate in some 

 varieties, larger and capitate in others, some even becoming fertile 

 and producing a few pollen grains. In the staminate flower the 

 ovary is wanting. 



ANTHES1S AND LIFE OF THE FLOWER. 



An thesis may take place at any time of the day or night, but it 

 seems to be most frequent early in the morning. Usually a large 

 number of buds will be seen to be opening about 6 or 7 o'clock and 

 if the weather is clear the petals will be fully expanded and the 

 anthers dehisced by noon. On exceptionally warm, bright days 

 the anthers sometimes dehisce before the petals are fully expanded. 

 Other flowers may open later in the day, and a few during the night. 



The stigma has every appearance of being in a receptive condition 

 immediately after anthesis, and in favorable weather retains its fresh 

 appearance for about two days. At the end of this time the pistil 

 usually commences to turn brown toward the stigmatic end, and the 

 ovary may commence to swell and assume a darker green color. 

 In many flowers, however, the ovary swells but little, the flower 

 drying up and falling off on the third or fourth day. 



In flowers which have opened before noon, the pollen usually 

 remains clinging to the anther for several hours, gradually being 

 brushed off by insects or eventually falling. Sometimes much pollen 

 will be left upon the anther until the second day. If the flower is 

 staminate, usually it will shrivel and fall by the third day. Conditions 

 seem to be vastly more favorable for pollination immediately after 

 anthesis than at any later time, because of the larger amomit of 

 pollen present. No indications of heteracmy were observed, the 

 stigma appearing to be receptive as soon as the flower opens, 

 usually not more than an hour or two before the anther dehisces. It 

 remains receptive for some time. 



POLLINATION. 



In spite of the close proximity of anther and stigma, the transfer 

 of pollen from the former to the latter does not seem to be accom- 

 plished easily. Both the stamen and the pistil retain an erect 

 position throughout, and the pollen as it is shed usually falls upon 

 the base of the ovary or upon the disk rather than upon the stigma. 



The normal method of transferring the pollen from the anther to 

 the stigma must be through the agency of insects. The white, 



