The showy parts of iris flowers are not clearly distinguishable between calyx and corolla, as in our Standard Blossom. The lowest parts, where you'd expect the calyx to be, are just as colorful and fleshy as the upper parts, where the corolla should be. When you want to refer to both calyx and corolla, or the showy parts where the calyx and corolla should be, you can call the whole structure a perianth. One specialized "perianth segment" of the iris blossom, situated where we'd expect a calyx's sepals to be, is the petal-like falls. The falls serves as a "landing pad" for pollinators. Notice how the falls in the flower above has bright lines leading into the blossom's mouth. These serve as nectar guides, directing pollinators toward the nectar.

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