In floral design, what type of flower is primarily used to create height?

In floral design, line flowers are specifically used to create height and add structure to arrangements. These flowers typically have long, tall stems and are often characterized by their vertical growth habit, which helps to lead the eye upward within a composition. Examples of line flowers include delphiniums and larkspur, which are commonly utilized for their height-providing qualities.

Mass flowers, while they provide fullness and can complement the design, do not primarily serve the function of adding height. Filler flowers are used to fill in gaps within an arrangement, creating fullness and texture, but they also lack the characteristic height that line flowers contribute. Form flowers have unique shapes and may create focal points, but they do not focus on verticality. Thus, line flowers stand out as the essential choice for establishing height in floral designs.