Britain's Prince William and the Duchess of Cambridge kicked off a nine-day Southeast Asia tour Tuesday with a viewing in Singapore of an orchid named in honor of William's late mother, Princess Diana.

Diana never saw the orchid, which was christened the "Dendrobium Memoria Princess Diana" a month after her death in a car accident in Paris in 1997.

William and his wife Catherine also had an orchid -- the "Vanda William Catherine" -- named after them at Singapore's National Orchid Garden, their first stop on a tour to celebrate Queen Elizabeth's Diamond Jubilee.

The royal couple also viewed the "Dendrobium Queen Elizabeth II" orchid, named for William's grandmother -- who has now ruled the British Commonwealth for 60 years -- on her visit to the country in 1972.

Orchid-naming is Singapore's way of welcoming important guests. The National Orchid Garden is also home to orchids named after state dignitaries including Nelson Mandela and Margaret Thatcher -- not to mention celebrity orchids such as the "Dendrobium Jackie Chan."

"Singapore has a longstanding tradition of naming orchids after important guests," said Poon Hong Yuen, the CEO of the National Parks Board.

"It is especially significant that we are able to name an orchid after Their Royal Highnesses, having named orchids after Her Majesty Queen Elizabeth II as well as the late Princess of Wales," said Poon.

William and Catherine' will also visit the Commonwealth nations of Malaysia, the Solomon Islands and Tuvalu on their tour of the region.