Article (website)  (16 Jan 2019)  
 
The name ‘Mary Queen of Scots’ is applied, in commerce, to at least two very different cultivars of Rosa pimpinellifolia. One of these is a plant with very distinct double purple flowers with pale backs to the petals (‘Bicolor’ in the 1820s sense) and rounded black heps; another as a plant with single pale pink flowers irregularly marked with darker pink which develop into elongated dark red pendulous heps (possibly one of a number of hybrids between R. pimpinellifolia and R. pendulina). It is very unlikely that either rose has any association whatsoever with the 16th century woman of that name. There is no evidence that any coloured double forms of Rosa pimpinellifolia were known in cultivation until about 1800 and the name does not occur until the 20th century.

Newsletter  (Sep 2018)  Page(s) 15.  Includes photo(s).
 
[From "Scots Roses And Related Cultivars Of Rosa Spinosissima", by Peter A. Boyd, pp. 8-17]
One particular rose provides a good example of the confusion that exists in the naming of Scots Roses and related cultivars. Thomas described one very distinctive rose, ‘Mary Queen of Scots’, in his 1962 book ..... That rose has typical Scots Rose character as regards form, foliage and black heps. The flowers are semi-double with the partially opened buds (the back of the petals) appearing white but opening to expose deep carmine on the front of the petals. The combination of grey-white buds and carmine creates a very striking effect.

Article (magazine)  (2008)  Includes photo(s).
 
'Mary Queen of Scots' .This name was used by Peter Beales (1997) for what seems to be a cultivar of R. x reversa with single pink flowers with irregular, darker pink shading and elongated, deep red fruits. This is quite different from the semi-double purple Scots Rose with this name described by Thomas (1962) which I discuss above. The single-flowered plant is what is normally sold by nurseries under the name 'Mary Queen of Scots', but the Thomas use of the name has priority. Ideally, the name of the single flowered cultivar should be changed. It flowers early, at the same time as 'Glory of Edzell'.

Book  (Apr 1999)  Page(s) 184.  
 
Mary Queen of Scots Pimpinellifolia. Breeder unknown, date uncertain... Gray-lilac and plum... Mary, queen of Scots; alias Mary Stuart; lived 1542-1587.

Book  (Sep 1993)  Page(s) 279.  Includes photo(s).
 
Legend has it that this very pretty rose was brought from France to Scotland by the beautiful and tragic lady whose name it bears … It is popular in Ireland. Description. Parentage unknown. Spring flowering. Fragrant.

Magazine  (1982)  Page(s) 1. Vol 4, No. 1.  
 
Editor [?]  Roses Imported From New Zealand.
This year some 'new' old roses have been imported from Trevor Griffiths in New Zealand, among those that arrived in January were: 
Mary Queen of Scots  - allegedly brought to Ireland from Scotland whence it had been carried by its namesake.  It is a plummy red with lilac gray buds.  Another Scots brier. 

Book  (1962)  Page(s) 84.  
 
'Mary Queen of Scots'. A most beautiful form grown by Lady Moore in Dublin, and the story goes that it was brought from France by the queen and eventually reached Northern Ireland, where it is found in many gardens. Lady Moore found it in 1921, in Antrim. The grey-lilac buds open to fairly double blooms, the surface of the petals being nearly as richly plum-tinted as in 'William III'. The grey-lilac and the plum make a fascinating contrast, a souvenir of a sad life. Probably 4 feet.