True lilies are bulbous perennial herbs with tunicless, scaly bulbs and single, erect stems. Leaves are mostly whorled or spirally arranged, with occasional alternate leaves between whorls. Flowers are showy and borne singly or in branched terminal inflorescences, each with six petal‑like tepals, six stamens, and a single pistil. In the eastern North American species, including all those native to Pennsylvania, the flowers are always part of a terminal inflorescence, even when only one flower is produced. The fruit is a dry, three‑valved, dehiscent capsule.