Polygala polygania and P. paucifiora. 125 



Now, whereas the plant is described and figured as having 

 simply two types of flower — conspicuous pink-purple ones 

 borne in nearly upright racemes, and minute, subterranean 

 cleistogamic ones, it bears later, on aerial shoots, an abundant 

 crop of green cleistogamic flowers, that are larger than the 

 underground ones. The branches bearing these tend to turn 

 downward ; so that a plant in August shows many, perhaps 

 nearly all of the shoots becoming positively geotropic, and 

 the foliage is mingled with masses of green cleistogamic 

 flowers (Plate XVI). 



We may now consider the various tj'pes of flower found in 

 this species, and later study the structural details of each. 



(i) The Chasmogamic or Conspicuous Flowers. 



These develop in long terminal racemes, are pink-purple in 

 color, and so are verj' noticeable among the low, flowering 

 herbs of summer. At Wood's Holl they appear first about 

 June 20, and continue to bloom in favorable seasons till about 

 the middle of August. The petaloid sepals are persistent, 

 and give to the maturing fruits at a distance the impression of 

 being still in flower. However, only two, or at most three, 

 flowers of each raceme are actually expanded at one time. 

 By marking flowers of many plants with threads it was found 

 that a new bud generally opens each day. 



Large numbers of them fail to set seed, so that later in the 

 season one finds to a large extent only the naked a.xes of 

 these racemes, or rows of seedless capsules. 



When seeds do mature properly from them, the length of 

 time required for full maturation is about five weeks. 



(2) The Subterranean Cleistogamic Flowers. 



At the same time that the first pink buds of the chasmo- 

 gamic flowers become visible, one may find by digging, nume- 

 rous pale branches arising from the base of the stenvand grow- 



