In botany, sessility (meaning "sitting", used in the sense of "resting on the surface") is a characteristic of plant parts that have no stalk. Flowers or leaves are borne directly from the stem or peduncle, and thus lack a petiole or pedicel. The leaves of most monocotyledons lack petioles.
Other examples of sessile flowers include Achyranthus, Saffron, etc.
Plant parts can also be described as subsessile, which is not completely sessile.