Book  (1915)  Page(s) 176.  
 
Clematis. — There is no more popular hardy climber than the Clematis.  One or two should be grown in the smallest garden.  They can be used to cover any structure from a few feet to 50 feet high.  A selection of different sorts will ensure a succession of flowers from April to October.
Snow White Jackmanii, pure white.

Website/Catalog  (1907)  Page(s) 66.  
 
Clematis in pots to plant out in spring and summer.
General Collection.
89 Snow-white Jackmanni (Jackmanii), "paper white".

Book  (1906)  Page(s) 53.  
 
Principal garden varieties of Clematis:
Jackmanni type.  (July to October.)
Snow-white Jackmanni... White.

Book  (1898)  Page(s) 66.  
 
Variétés Horticoles
1er Groupe.—PATENS
Section III. — Jackmani.
Smith's Snow white (Smith).  Fleur blanc pur.

Magazine  (23 Jan 1892)  Page(s) 78.  
 
Hardy Shrubs that have Received Certificates During 1891.
Clematis Smith's Snow White Jackmani, though not actually a shrub, is of a woody character, so that it is entitled to a place herein.  It is a pure white-flowered variety, but little can be said as to its merits, unless it is tested out of doors under the same conditions as Jackman's Clematis.

Magazine  (8 Aug 1891)  Page(s) 156.  
 
[Advertisement]
Two Grand Novelties.
A pure white bedding clematis, and the fern which has lately received so many of the highest awards and proofs of admiration.
Clematis, Smith's Snow-White Jackmanii.
The flowers are paper-white, about the same size as those of the old purple Jackmanii, but produced in even greater profusion.  It is unrivalled for beds, and also for climbing.  Ready in August.  7s., 6d. each. [...]
Richard Smith & Co.,  Nurserymen and Seed Merchants, Worcester.