On 21/11/2013 17:24, David Hill wrote:

I always understood that the Myrtle in Queen Victoria's bouquet was
rooted and has provided sprigs of Myrtle in every Royal brides bouquet
since then.

http://www.english-heritage.org.uk/daysout/properties/osborne/garden/italian-terraces/

"...the royal myrtle (Myrtus communis) growing against the walls of
the central flight of steps. This sweetly scented Mediterranean plant
was grown from a sprig presented to the Queen from Albert's
grandmother when they left his ancestral home, Gotha, in 1845 and has
been used in royal wedding bouquets ever since."
--
Phil Cook