sessile

American  

[ses-il, -ahyl] / ˈsɛs ɪl, -aɪl /

adjective

1. Botany. attached by the base, or without any distinct projecting support, as a leaf issuing directly from the stem.

2. Zoology. permanently attached; not freely moving.

---

sessile British  

/ ˈsɛsaɪl, sɛˈsɪlɪtɪ /

adjective

1. (of flowers or leaves) having no stalk; growing directly from the stem

2. (of animals such as the barnacle) permanently attached to a substratum

---

sessile Scientific  

/ sĕs′īl′ /

1. Permanently attached or fixed and not free-moving, as corals and mussels.

2. Stalkless and attached directly at the base, as certain kinds of leaves and fruit.

---

Other Word Forms

• pseudosessile adjective
• sessility noun
• subsessile adjective

Etymology

Origin of sessile

1715–25; < Latin sessilis fit for sitting on, low enough to sit on, dwarfish (said of plants), equivalent to sess ( us ) (past participle of sedēre to sit ¹ ) + -ilis -ile

Example Sentences

It has been trying to restore the woodlands by introducing downy birch, sessile oak, hazel, willow, aspen and alder as well as endangered tree species such as Arran whitebeam.

From BBC • Apr. 28, 2025

Researchers learned that sessile invertebrates -- those that stay in one place, such as mussels and barnacles -- became more abundant during the study period, while seaweed species like kelps declined.

From Science Daily • Jun. 4, 2024

Studies of other kinds of deep-sea disturbances, including deep-sea trawling and oil and gas operations, have suggested that sessile animals are especially vulnerable, sometimes taking decades to recover.

From Scientific American • Jul. 18, 2023

Many sessile organisms feed on organic material that drifts down from upper layers in the water column.

From Scientific American • Jul. 18, 2023

Pale or glaucous; stem simple, 1–2° high; leaves sessile, oblong- or linear-lanceolate, entire, or the lower runcinate-pinnatifid; heads few and large, racemose, erect on scaly-bracted peduncles; involucral scales imbricated in 3 or 4 ranks.

From The Manual of the Botany of the Northern United States Including the District East of the Mississippi and North of North Carolina and Tennessee by Gray, Asa