Book  (2007)  
 
'Keystone' LCl, dy, 1904, Dingee & Conard. Includes description.

Book  (1936)  Page(s) 384.  
 
Keystone (multiflora) Dingee & Conard 1904; deep lemon-yellow, medium size, double, fragrance 5/10, floriferous, growth 7/10, climbing, hardy.

Book  (1920)  Page(s) 177.  
 
In "List of American Roses:" Keystone. Mult. (Dingee & Conard, 1904).

Website/Catalog  (1914)  Page(s) 19.  
 
Roses for the People
Keystone, Climbing Polyantha
(Dingee, 1904)
Deep lemon-yellow; full and double; magnolia fragrance; free bloomer; vigorous.

Website/Catalog  (1913)  Page(s) 45.  Includes photo(s).
 
Climbing Tea and Noisette Roses
Keystone
The blossoms of the Keystone Rose are a deep lemon-yellow in color and have a fragrance resembling the magnolia. They are double and finely formed, and appear with great frequency. The buds are shapely and pefectly formed. The plant is unusually hardy and practically immune from insects. It grows stronger than the majority of Climbing Roses, and attains a great age. Unlike many Climbing Roses, the plant seems to take added vigor with the added years and the production of flowers is  not diminished when the plant is cared for. The lustrous deep green foliage is both distinctive and beautiful.

Website/Catalog  (1910)  Page(s) 29.  
 
The Ever-blooming Climbing Roses.
Climbing Roses are of great utility in beautifying porches, fences, arbors, etc.
Price: 30 cents each; $2.50 per 12; $30.00 per 100.
Keystone.  Perfectly hardy, very free bloomer and exceedingly vigorous; flowers are perfectly double and a deep lemon color; very fragrant; one of the fastest growers among the climbers.

Website/Catalog  (1907)  
 
In "Climbing Tea and Noisette Roses:" Keystone. Deep lemon-yellow; flowers double, of exquisite form and fragrance. Perfectly hardy and blossoms with remarkable freedom.

Book  (1906)  Page(s) 82.  
 
5.254.  Keystone,  Hybride de Thé,  Dingee  1904  jaune

Website/Catalog  (1904)  Page(s) 36.  Includes photo(s).
 
Our Sensational New Rose... "Keystone"
The First and Only Hardy, Ever-blooming, Yellow Climbing Rose.
Introduced and for sale only by The Dingee & Conard Co.
This great new Rose is the first hardy, ever-blooming, Yellow Climbing Rose.  It has been thoroughly tested, and for want of space we will give but a brief renumeration of its strong points.  It is a freer growing Rose than any other climbing variety in the list, is perfectly hardy everywhere, blooms with wonderful freedom, is absolutely impervious to insect attacks and has a vigor of constitution found in no other Rose.  The open flower is perfectly double, resembling Clotilde Soupert; buds beautifully formed; color deep, lemon yellow, similar to Coquette de Lyon.  Fragrance delicious, like that of Magnolia blossoms.  It readily attains a height of 15 feet in a single season, branching freely, and has withstood, undamaged, Winter after Winter, in the most exposed situation, without protection, constant temperatures of 10 to 20 degrees below zero.  It possesses every feature that a good Rose should have, and the fact that it is free-blooming makes it almost indispensable.
The entire stock of 'Keystone' is in our possession, and genuine plants can be secured only from us.  
Strong plants, 25 cents each; 5 for $1; $2.25 per dozen.  Two-year-old plants, 50 cents each; 5 for $2, by Express.