sessile

Etymology

From Latin sessilis (“sitting”), from sessus, perfect passive participle of verb sedeō (“to sit”), + adjective suffix -ilis. Compare session.

adj

1. (zoology) Permanently attached to a substrate; not free to move about.
   a sessile oyster
2. (botany) Attached directly by the base; not having an intervening stalk; stalkless.
   The pileus is sessile, or sometimes narrowed at the base into a short stem, the caps often numerous and crowded together in an overlapping or imbricate manner. 1903, George Francis Atkinson, chapter VII, in Studies of American Fungi. Mushrooms, Edible, Poisonous, etc., 2nd edition, New York: Henry Holt