One's off-duty wardrobe: Queen gave rare glimpse of her more private style in an unbuttoned cosy cardigan and a loose blue dress as she planted a rose in memory of Prince Philip who would have turned 100 today 

• The Queen, 95, has marked what would have been Prince Philip's 100th birthday
• She received a rose plant which was planted in a memorial at Windsor Castle
• The royal was seen in rare casual outfit including cardigan and blue floral dress

The Queen has offered a glimpse at her more private style as she paid tribute to Prince Philip to mark what would have been the Duke's 100th birthday today. 

The royal, 95, received a rose plant named 'the Duke of Edinburgh', which was planted in the East Terrace Garden in a memorial at Windsor Castle earlier this week. 

In photographs released last night of the poignant occasion, the Queen could be seen wearing a vibrant blue midi dress featuring tiny white flowers, which she paired with an unbuttoned white cardigan, which had been rolled up at the sleeves.

The outfit is a far cry from the Queen's usual formal wear, with the royal renowned for her love of colourful coat dresses and matching hats. 

She accessorised with a pair of her trusty pearl earrings and kept her makeup natural - adding just a pop of pink lipstick. 

Meanwhile the royal also donned a set of dark sunglasses and could be seen carrying a colourful headscarf in her hands.

The Queen often works with her personal assistant and close friend, Angela Kelly to put together the perfect outfit for official engagements. 

Angela's full title is Her Majesty's Personal Adviser and Curator (The Queen's Jewellery, Insignias and Wardrobe), Senior Dresser and In-house Designer. 

Angela rarely gives interviews but once disclosed: 'We are two typical women. We discuss clothes, make-up, jewellery.'

The Queen values the opinion of her meticulous personal assistant and has gradually over the years given her free rein when helping her create a look for an event.

Angela is credited with keeping the Queen's style relevant, and for adding a 'touch of bling'.

Despite the Queen's advancing years she has been prepared to embellish her style, under Angela's direction, as a nod to modern times. 

The monarch received the shrub last week from the aptly-named Keith Weed, President of the Royal Horticultural Society (RHS). 

The beautiful 'Duke of Edinburgh' rose was planted in the East Terrace Garden which Her Majesty will be able to look out onto from her private rooms.

The deep pink commemorative perennial plant was officially named in memory of the Duke who died aged 99 on April 9.  

Mr Weed told the Queen: 'It’s a rose named the Duke of Edinburgh Rose to mark his centenary and it’s a commemorative rose for all the marvellous things that he did over his lifetime and for everyone to remember so much that he did.”

The Queen replied: 'It looks lovely' before added that the tribute was 'very kind'.

With the flower not in bloom as her presented it to The Queen, Mr Weed joked: 'Right now with a cold Spring and nature being a bit behind it doesn't look so lovely but that’s what it will look like', pointing to a picture of the rose.

The 95-year-old monarch watched as Windsor's head gardener Philip Carter planted it at the front of the mixed rose border.

She remarked that after the cold May 'nothing has flowered here much'.

Royalties from the flowers' sale will go towards the Duke of Edinburgh Award’s Living Legacy Fund, which helps young people take part in the scheme.