Magazine  (1966)  Page(s) No. 164, p. 275.  
 
Clematis (hybrids)...
From France. Plants presented by Andra Girault, Horticulteur-Pepinieriste, Orleans (Loiret). Received Nov. 18, 1959.
...261358. 'Rubella'.

Website/Catalog  (1924)  Page(s) 107.  
 
Rubella (Jackmani). Nombreuses fl. moyennes, violet pourpre.

Website/Catalog  (1912)  Page(s) 78.  
 
Summer and Autumn Clematis.
In bloom from July to October.
These flower upon the wood of the current year's growth, and should therefore be pruned to five or six eyes.  The varieties most suitable for bedding are marked thus* 
*Rubella, rich velvety claret colour...  1s. 6d.

Magazine  (Aug 1910)  Page(s) 308.  
 
Association horticole lyonnaise Procès-verbal de l’Assemblée générale du samedi 16 juillet 1910...
Examen des Apports. — Sont déposés sur les tables les produits suivants : .... — Par M. F. Morel, pépiniériste, à Lyon-Vaise:  .... 3° Une collection de clématites en fleurs coupées, parmi lesquelles ; Rubella, Jackmanni, Etoile violette, Madame Furtado Heine, Vit. alba luxurians, intermedia, recta cœrulea, Mandshurica, Davidiana, coccinea.
....A M. Francisque Morel .... pour sa collection de Clématites, prime de première classe.

Book  (1907)  Page(s) 144.  
 
It is a matter of interest that hybrid clematis may be grown in beds, and in this case require to be trained over hoops to form a low convex shield-shaped mass of green leaves and gorgeous flowers.  For this purpose the best are Jackmanni, with violet-purple flowers; Rubro-violacea, with maroon-purple flowers; Alexandra, reddish-violet; Magnifica, purple and red; Rubella, deep claret; Star of India, reddish-plum with red stripe; Tunbridgense, reddish-lilac with mauve stripe.

Book  (1906)  Page(s) 53.  
 
Principal garden varieties of Clematis:
Jackmanni type.  (July to October.)
Rubella... Rich claret-purple.

Book  (1898)  Page(s) 66.  
 
Variétés Horticoles
1er Groupe.—PATENS
Section III. — Jackmani.
Rubella (Jackman).  Fleur violet pourpre, de belle forme.

Magazine  (Feb 1879)  Page(s) 50.  
 
The Clematis.
Here is a list of some of the best and most distinct of the [summer]-flowering varieties: Alexandra, Jackmanni, Lady Bovill, lanuginosa, lanuginosa nivea, magnifica, rubella, Thomas Moore, Tunbridgiensis, vilustina purpurea, and viticella rubra grandiflora.

Magazine  (1877)  Page(s) 260, 271.  
 
p. 260: Rubella. — Fl. Mag., V, 1866, pl. 310.
Rubella. Flore des Serres, 1874, XX, pl. 2050-54.

p. 271: Clematis rubella (Jackman), Flore XX, s. des Jackman; pourpre.

Website/Catalog  (1875)  Page(s) 79.  
 
CLEMATIS. Virgin's Bower.  Waldrebe, Ger. Clematite, Fr.
The Clematis are elegant, slender branched shrubs, of rapid growth, handsome foliage and beautiful large flowers of all colors.  The newer varieties introduced within the last five or six years are great acquisitions.  Either in the open ground as pillar plants, bedding plants, single plants in masses or about rock-work, or cultivated in pots or tubs, the Clematis cannot be excelled.
We append the following from the English "Gardener." Jackman's Clematises: "They are magnificent; and more than this, they do give us some of the grandest things in the way of creepers the horticultural world has ever seen, making glorious ornaments either for walls, verandahs, or rustic poles or pillars, varying in color from deep rich violet hue to dark velvety maroon, and in the newer seedling forms, beautiful shades of pale bright blue."
They will stand the severest Winters if the roots are slightly covered.
Class I. Perpetuals, Flowering in the Summer and Autumn, on Summer Shoots.
C. rubella.  Flowers of a rich velvety claret color.  $1.00.