Book  (2010)  Page(s) 93.  
 
Peter Harkness. An Update on Persica Hybrids.
....it was decided to introduce four of them, rather than see them perhaps lost for ever.
Xerxes [HARjames] (R. persica x 'Canary Bird') was pollinated as far back as 1970, and beautiful because the red 'eye' showed to brilliant effect against its sizeable bright yellow petals. It made an upright 2 x 1.2m (6 x 4ft) shrub with neat foliage but proved less easy to propagate, and was not destined for a long run in commerce.

Book  (Apr 1993)  Page(s) 645.  
 
Xerxes Shrub, flowers rich yellow with scarlet red eye at base, reverse yellow [yb], 1989, (HARjames); H. persica x 'Canary Bird'; Harkness, R. & Co., Ltd.

Book  (1985)  Page(s) 166.  
 
The most interesting project was Rosa persica, a difficult species, of which I probably held the largest stock ever grown outside its native regions. The object here was to raise a fertile hybrid, but although we got in the end over a hundred, some very beautiful, and notable as the first recorded since 1836, they were all sterile and bloomed only in the summer. Their beauty lay in a dark red eye at the centre of the bloom. I obtained them single and double, yellow, pink, salmon and orange. Having put a lot of work into this bit of pioneering, I thought we might introduce two of the hybrids, and sent them to the Royal National Rose Society's trials. No interest was expressed, and I accepted the fact that they were not yet suitable for gardens, although of great botanical interest.