Amphicarpaa monoica. 3-7 



blance to the mature one- in Fig. 7. I" Pig- 9 the style 

 has the characteristic erect position and the perfect capitate 



stigma. 



Plate XXVIII, Fig. 2, is a transverse section through the 

 ovary of the green aerial flower. The macrosporanghim, 

 with the enclosed macrospore, may be readily studied. 

 Other sections which were examined showed variation in 

 height and perfection of the stamens. 



These flowers have been seen upon plants bearing purple 

 blooms, but appear about a mouth later. Some of these 

 were in the green-house, others out of doors, alike in the 

 Botanic Garden and in the country. As late as the first 

 week in October, the aerial green flowers were found in bud 

 condition. There is no doubt they would have matured 

 fruit, had the weather continued favorable. 



Plants grown in poor soil, or where there was too much 

 sun, or in too much shade, never produced any but cleisto- 

 gamous aerial flowers. 



' Meehau 1 " calls attention to the two kinds of aerial 

 flowers ; but he does not describe their location upon the 

 plant, nor their structure correctly. He regards the apeta- 

 lons flowers as pistillate, "receiving pollen from petalife- 

 rous blossoms." He denies the presence of pollen in these 

 imperfect flowers, and therefore does not wish to call them 

 cleistogamic. He does not note the time when this 

 latter type appears. 



Subterranean Flowers. 



Some weeks before Amphicarpaa blossoms above ground, 

 the cotyledonary axillary runners have already formed 

 buds. It has been already stated that the runners from 

 the axils of simple leaves are geotropic, and the secondary 

 branches upon these also exhibit the same physiological 

 characteristic. While the cotyledonary shoots mentioned 

 are colorless, those from the simple leaves frequently are 

 deeper purple-green than the remainder of the plant. As 

 they lie upon the ground, often the main branch thick- 



