MULES OR HYBRIDS 63 



produced ; these strike root freely, treated in the same 

 way as advised in the case of that hybrid. Rust some- 

 times attacks the tips of the leaves, which it is advisable 

 should be cut off when first observed, in order to prevent 

 infection to others. Otherwise, the plant presents no 

 difficulties in its cultivation. 



D. Quelteri is another dark-crimson form. 



D. Rose Perpetual is supposed to be a plumarius hybrid. 

 The plant is valuable in flowering continuously far into 

 autumn. 



Z). Rosetta produces a neat flower of a pinky shade. 



D. Spencer Bickham resulted, about 1900, from a cross 

 between D. c&sius and D. deltoides. The flowers are 

 deep rosy-crimson, and the plant growing only five inches 

 in height is well suited to the rockery. 



D. striatiflorus produces striped flowers, and is a variety 

 that has been in gardens during many years. It is, 

 perhaps, more bizarre than beautiful. 



Z>. superbus, though bearing the name of a species, has 

 nothing in common with that plant. This is a dark- 

 crimson double-flowered mule, exceedingly fragrant, and 

 possessed of a perpetual habit, and a plant altogether 

 worthy attention. 



D. superbus garnerianus. This has already been noted 

 in the chapter on Species. It is commonly called 

 D. s. Gardneri. 



