[From The Rose Garden (Tenth Edition), by William Paul, p. 252:] The Hybrid Bourbon Roses are in greater part descended from the French or Provence crossed with the Bourbon...

[From Old Roses, by Ethelyn Emery Keays, pp. 168-169:] William Paul [divided Hybrid Perpetuals into two classes, one] the Hybrid Perpetual derived from the Damask, and the Hybrid Bourbon, derived from the Bourbon...