Rhododendron is a bay filly with no white markings bred in Ireland by Orpendale, Chelston & Wynatt, breeding companies associated with the Coolmore Stud organisation.

His other progeny include Cape Blanco, Frankel, Golden Lilac, Nathaniel, New Approach, Rip Van Winkle, Found Minding and Ruler of the World.

[6] In August she was reunited with Heffernan when she was moved up in class for the Group Two Debutante Stakes at the Curragh and started 11/8 favourite ahead of Rehana and the O'Brien-trained Brave Anna.

Hydrangea set the early pace with Rhododendron settled behind the leaders before moving up to join her stable companion approaching the final furlong.

After being repeatedly blocked in her attempts to make progress in the last quarter mile she was switched sharply left and finished strongly but was beaten two lengths into second place by her stablemate Winter.

She was then sent to France for the Prix de Diane at Chantilly Racecourse sixteen days later but had no chance to show her true form as she was pulled up by Moore after breaking a blood vessel.

Ridden by Seamie Heffernan she tracked the leaders before going to the front in the straight and held on "gamely" in the closing stages to win in a five-horse blanket finish from Hydrangea, Lady Frankel, Wuheida and Left Hand.

[13] For her final run of the year Rhododendron was sent to California for the Breeders' Cup Filly & Mare Turf over nine furlongs at Del Mar on 4 November and started the 4/1 second favourite behind Lady Eli.

Rhododendron began her third campaign by taking on male opposition for the first time and finishing fourth behind Cracksman in the Prix Ganay over 2100 metres at the re-opened Longchamp Racecourse on 29 April.

After racing close behind the leaders, the filly produced a strong late run, caught Lightning Spear on the line and won by a short head.

[15] In the Queen Anne Stakes at Royal Ascot Rhododendron started second favourite but never looked likely to win and came home ninth of the fifteen runners behind Accidental Agent.

An attempt to repeat her 2017 success in the Prix de l'Opéra ended in failure as she finished twelfth, more than 20 lengths behind the winner Wild Illusion at Longchamp Racecourse on 7 October.

In the official European Classification of two-year-olds for 2016 Rhododendron was given a rating of 116, making her the second best juvenile filly of the season, five pounds behind Lady Aurelia and equal to Brave Anna.