308 IOWA ACADEMY OF SCIENCE Vol. XXVI, 1919 



son county. There was the deep red to the pure white and between 

 these extremes various shades and combinations of colors that 

 seemed to show a gradual transition from one extreme to the 

 other. 



Number of petals. — Very rarely does the number of petals exceed 

 five. In Dickinson county there were two groups of roses in which 

 the petals numbered six, seven, eight, nine, and even ten. 



The petals are commonly obcordate but a few cuspidate forms 

 were found. 



Feuit 



The dark red fruits are commonly globose though some are 

 pyriform. 



One would be inclined to think that in a species exhibiting' so 

 much variation at least varietal subdivision could be made but the 

 variation is not concomitant. One feature changes without ap- 

 parent connection with any other. It exhibits what Dr. Gray called 

 promiscuous variation. 



This type of variation is well illustrated in the following examples. 

 The features underscored are the exceptions to the general rule. 



Example 1. Stem zuitJi only an occasional prickle, pedicel pubes- 

 cent, stipules dilate, leaflets eleven, inflorescence corymbose, hypan- 

 thium glabrous, rhachis pubescent, sepals glandular-hispid. 



Example 2. Stem very prickly, pedicel glabrous, stipules dilate, 

 leaflets seven to nine, inflorescence 2-corymbose, hypanthium 

 glabrous, rhachis pubescent, sepals glandular-hispid. 



Dilate stipules is an exception common to both the above examples 

 but note the difference in the accompanying variations. In example 



1 they are almost naked stem and a pubescent pedicel and in example 



2 they are seven to nine leaflets and a few-flowered inflorescence. 

 In another specimen dilate stipules were accompanied by a 

 deciduous-prickly stem. 



In the above examples variations arc cited which accompany 

 dilate stipules, but narrow stipules is the prevailing form, llie 

 following examples will show that variations also accompany nar- 

 row stipules. 



Example 1. Stipules narrow, sepals spreading and pubescent, 

 pedicel pubescent, hypanthium glabrous, stem very prickly, leaf- 

 lets nine to eleven, rhachis pubescent, inflorescence corymbose. 



Example 2. Stipules narrow, deciduous-prickly stem, leaflets 

 seven to nine, rhachis pubescent, hypanthiums and pedicels glabrous, 

 sepals glandular-hispid, inflorescence corymbose. 



