A chrysanthemum
The chrysanthemum was a flowering plant from Earth which produced large, many-petaled blossoms of various colors.
Chrysanthemums were used in the floral arrangements at a reception held for the Evora aboard the USS Enterprise-E in 2375. The Evora delegation apparently found the flowers quite appetizing, prompting Jean-Luc Picard to suggest that a balsamic vinaigrette be prepared to accompany the flowers. (Star Trek: Insurrection)
In order to test the properties of the symbiogenetic orchid found on a planet in the Delta Quadrant, Harry Kim beamed one chrysanthemum, one clematis, and one of the native flowers up to the USS Voyager. The three plants were merged into one during transport. Later, the crew was able to split the three plants up again. (VOY: "Tuvix")