sessile

Adjective

sessile (not comparable)

1. Permanently attached to a substrate; not free to move about.
   • a sessile oyster

   Synonyms:

   attached, fixed, immobile, immotile, immovable, inanimate, inert, lifeless, static, rigid

   Antonyms:

   mobile, motile, vagile, ambulatory, animate, kinetic, motive, movable

2. 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
   • The sporophyte foot is also characteristic: it is very broad and more or less lenticular or disciform, as broad or broader than the calyptra stalk[…], and is sessile on the calyptra base[…]1992, Rudolf M[athias] Schuster, The Hepaticae and Anthocerotae of North America: East of the Hundredth Meridian, volume V, Chicago, Ill.: Field Museum of Natural History, →ISBN, page 5