CLEISTOGAMOUS FLOWERS IN THE GENUS VIOLA. 4.7 



Vitis rotundifolia, the Muscadine grape, is not unfrequent here. 

 It is a very peculiar species and almost itself constitutes a genus. Its 

 bark is continuous, never shreddy, smooth and of a whitish color. 

 Its large purple fruit is of a peculiar flavor, grows in small clusters, 

 and when ripe may be easily shaken from the stem. 



In coming down a mountain ravine I saw the handsomest sight 

 of my journey. It was an Euonymiis atropiirpureiis in the full per- 

 fection of its fruiting. Its beauty was only surpassed by a tree form 

 of its cousin, E. Americajius, which I once saw in extreme south- 

 eastern Kansas. E. atropiirpureiis is not a climber and it seldom 

 trails, but like SopJiora affinis and other weak-stemmed trees, it likes 

 to grow up in a crowd of stronger shrubs, and while never attached 

 to, sometimes lean upon them. 



Kansas City, Kansas. 



THE CLEISTOGAMOUS FLOWERS IN THE GENUS 



VIOLA. 



By Willard N. Clute. 



IN VIEW of the increasing tendency toward giving the cleisto- 

 gamous flowers of violets a prominent part in the diagnosis of 

 the species, it may not be amiss to call attention to the instability 



of such characters. We are accustomed to speak of a cleisto- 

 gamous flower as something definite and fixed, but nature has no such 

 hard and fast distinctions. By careful watching through a single 

 summer one may see the so-called cleistogamous flowers slowly turned 

 to showy ones or vice versa by numerous small gradations. Some 

 years ago, in the pages of MeeJians' Monthly, I advanced the theory 

 that the cleistogamous flowers in Viola, at least, are largely a matter 

 of temperature, and subsequent observations have only served to con- 

 firm me in this opinion. I have not applied this test of temperature 

 to other genera in which cleistogamous flowers occur, but that the 

 evidence is strongly in favor of this theory regarding Viola, a few 

 facts will show. 



Taking our common blue violet, it will be found that early in the 

 year, when the weather is cool, it produces an abundance of showy 

 flowers, but as the temperature increases, the production of petalifer- 

 ous blossoms ceases and cleistogamous flowers appear. Late in year, 

 even after frosts are common, the showy flowers are noticed again. 

 Now, if we begin early enough in autumn to inquire into the origin of 

 these petaliferous flowers, we shall find that they are evolved directly 

 from the cleistogamous ones. At first, only one or two embryonic 



