Tiger flower is sometimes confused with tiger lily, but the plants belong to entirely different families. Tiger lily is a true lily from the Liliaceae family, while tiger flower is closely related to iris. Both are summer bloomers, but tiger lily is hardy as far north as zone 3, while tiger flower is a warm-weather perennial. Both plants have flowers with distinctive speckled throats, but the blossoms on tiger flower are fairly wide open and last for only a day, while the blooms on tiger lily have a distinctive trumpet shape and remain open for up to a week. Most importantly, tiger lily, as a true lily, is toxic to people and pets, while tiger flower is entirely harmless and even edible in some circumstances.