Book  (11 Jun 1993)  Page(s) 68.  
 
Seedling of R. rubrifolia x unknown R. rugosa hybrid. Central Experimental Farm (Canada) 1928. Description... Profuse large single rose-purple blossoms with white centers.

Book  (Apr 1993)  Page(s) 8.  
 
Algonquin Shrub, flowers purplish rose, center white, 1928, R. rubrifolia x R. rugosa hybrid seedling; Central Exp. Farm... hardy

Book  (1953)  Page(s) 66.  
 
Algonquin - 28

Book  (Jan 1946)  Page(s) 32.  
 
Algonquin, C.E.F. Ottawa R28-13-02 seedling of a former hybrid of R. rubrifolia x R. rugosa. The foliage is large and dull yellow-green in colour. The large flat single flowers are purplish-rose, shading to white at the centre. It has large bottle-shaped red fruits that are very ornamental.

Book  (1946)  Page(s) 51.  
 
In "Progress in Breeding Hardy Roses," Isabella Preston says,

Algonquin, an open-pollinated seedling of a rugosa-rubrifolia hybrid, has made a bush ten feet tall and eight feet wide but it is very different in appearance to Carmenetta. The foliage is dark green with faint purplish shadings and is large and leathery. The single flowers are Rhodamine Purple with white centers and are almost three inches across. They grow in large clusters and the plant is very showy for two or three weeks in June. The large bottle-shaped fruits are very handsome, and in most years are borne in great profusion.

Book  (1940)  Page(s) 91.  
 
In "Central Canadian Rose-Breeding" Isabella Preston, after describing the breeding of 'Carmenetta', says

Many seedlings were raised from the reciprocal cross but as all had green leaves, none was considered worthy of naming. Open fertilized seeds were sown, and a number of seedlings raised, a few of which have been named. Algonquin (R.28.13.02) grows five to six feet tall. The foliage is large, yellow-green. Flowers are large, single, rhodamine-purple, shading to white in the center, in clusters of one to three. Calyx limb is long and widens towards the tips. Hips are bottle-shaped and attractive.