Magazine  (24 Jun 1932)  Page(s) 34.  
 
Rosa rugosa and its hybrids.
...It would seem as though many of these Rugosa hybrids might be useful in producing new varieties of hardy roses. [...] For the convenience of those amateurs who are doing breeding work with roses, the pollen of the hybrids in the Arboretum's collection has been examined in the Cytological Laboratory.  In the following discussion the percentage of fertile pollen, as determined by microscopical examination, is reported for each hybrid where buds were available for study.
Schweidnitzia 
Pollen fertility 10%.
The flowers are white and semi-double.  The bush is low, the foliage dark green and leathery.