U,K, GREETINGS stamps.
The whole 1977 series issued by the Royal Mail as it looks in the presentation pack.
In addition to the stamps there is a sheet of stickers to be used on the envelopes.
Magnolia, Irises, Tulips, Camellias Fuchsia, Gazania, Hippeastrum and Passiflora all to be found in Mediterranean gardens, I am not so sure about Gentians.
I had found references to all these plants in THE MEDITERRANEAN GARDEN so just go back through the last ten + posts in this thread to find them.