38 Dorsey: VARIATION IN FLORAL STRUCTURES OF VITIS 
between members of the floral organs in the several whorls; and 
this relation obtains when there occurs either an increase or 
decrease in the number of parts of the flower. 
FLOWER TyPEs: Vitis may be regarded as dioecious, polygamo- 
dioecious, or perfect. Individual vines of V. vulpina and V. bicolor 
occur in the wild in either the staminate or the perfect form. By 
staminate is meant forms in which no well-developed pistils are 
produced. 
In the open the staminate plants occur in the greater number; 
of the 347 vines observed by the writer, 218 were staminate and 
129 perfect. In these species the reflexed or recurved type of 
stamen was an invariable accompaniment of the perfect flower; 
that is, in no case were upright stamens found along with well- 
developed stigmas. Two wild vines, however, of V. vulpina were 
found in which the stigmas were partially developed. Yet the 
upright stamen form is to be regarded as signalizing the typical 
- perfect flower, since, as is shown later, pollen development in the 
reflexed stamen may be poor. 
As has been observed by Engelmann (’94) and others, the 
cultivated varieties, on the other hand, have two distinct floral 
types which are quite constant for-all of the individual vines of a 
variety. These types are both perfect forms, the one possessing 
upright and the other reflexed or recurved stamens. As might be 
expected, the staminate form is not found under cultivation, except 
In rare instances where it may be 
of the self-sterile varieties, 
It may be of interest to consider briefly the significance of the 
perfect form of flower, in general. From the standpoint of the 
evolution of the floral forms, either we may regard the perfect 
flower as the original form, and the pistillate and staminate forms 
as being derived from this: or we may consider the original form 
to have had diclinous flowers, and the perfect form to have been a 
later development. 
grown in order to pollinate some’ 
There occur in the known species of Vitis, flowers (1) with 
stamens upright and pistils abortive (functionally staminate), 
(2) stamens upright and pistil fully developed and functional 
(perfect), and (3) stamens reflexed, pollen more or less abortive, 
and fully developed pistils (sometimes functionally pistillate). 
