What flower features are shared by many plants in Gentianales?

Many plants within the Gentianales order share several distinct floral characteristics:

• Petal Structure: The flowers are typically showy and regular (alike in size and shape). A defining feature is that the petals are usually joined together, often forming tubular corollas that can range from funnel-shaped to bell-shaped.12
• Bud Arrangement: When in the bud stage, the petals are arranged in a regular overlapping pattern (imbricate or convolute) or are valvate (nonoverlapping).1
• Ovary Position: In most members of the order, the carpels are united to form a compound ovary that is positioned superiorly within the flower. The notable exception is the Rubiaceae family, which generally features inferior ovaries.1
• Reproductive Anatomy: The ovules possess a single integument, and the nucellus is one-layered. In the Gentianaceae family specifically, the stamens are attached to the inside of the corolla tube and appear in the same number as the petals.12

These features contribute to the order's status as a significant source of ornamental plants.1