A hair trigger is disturbed, releasing a door latch that swings open inwardly with a rush of water. The walls of an elastic trap bulge and the door closes instantaneously on its unsuspecting prey, trapping and devouring it.

Although this might sound like a scene from a horror flick, it actually describes feeding time for the bladderwort (Utricularia)---a carnivorous plant that grows in slow-running streams and shallow ponds across Canada. The flat-leaved bladderwort (Utricularia intermedia) is one of the intriguing wildflowers that Canada Post features this year in its ongoing series, Flowers.

Issued on December 19, 2006, this set of stamps includes denominated definitives for U.S., international and domestic oversized mailings. These stamps are part of the same series that features the new nondenominated PERMANENT^™domestic rate stamp (spotted coralroot) released in November 2006.

"This is a particularly exciting issue for us," says Danielle Trottier, Manager of Stamp Design and Production at Canada Post. "The souvenir sheet appears on the official first day cover (OFDC), along with a beautiful cancel depicting a dragonfly. What makes this a really unique OFDC is that this is the first time that a full set of definitives, including the non-denominated PERMANENT^™ domestic rate stamp, appears on the souvenir sheet," says Trottier.

The flat-leaved bladderwort appears on the U.S. rate (93¢) stamp, while the little larkspur (Delphinium bicolor) is featured on the international rate ($1.55) and the marsh skullcap (Scutellaria galericulata) is used for the domestic oversized rate ($1.10).

The little larkspur, a beautiful flower native to dry grasslands in southern British Columbia, Alberta and Saskatchewan, can be poisonous in large quantities. When mixed with alum, the juice from the larkspur's flowers produces blue ink. Marsh skullcaps, which usually come in pairs, have blue or pink-purple flowers streaked with white. They can be found in wet habitats from Newfoundland to the Yukon.

Stamp designer Monique Dufour says that, even though she and partner Sophie Lafortune have been working on the flower definitives for a few years, there are still challenges to the design. The Flowers definitives are some of the tiniest stamps produced by Canada Post. "At that size," says Dufour, "fine lines are invisible and the editing process for the illustration requires special care."

Dufour and Lafortune created these and past Flowers stamps using the illustrations of Sigmond Pifko. "I love flowers and find them particularly inspiring," says Pifko, who typically uses 10 to 30 different photographs to compose one flower illustration. He manipulates the composition through traditional drawing techniques and creates the final beautiful works of art on illustrator board using a combination of acrylic, guache and watercolour.

Printed on Tullis Russell Coatings, the flat-leaved bladderwort, little larkspur and marsh skullcap are all available in six-stamp booklets and 50-stamp coils. With such beautiful designs, this set of Flowers stamps is sure to be wildly popular for collecting or sending.