thickening

saostusaine

saostaminen, saostus

syvenevä

mutkistuva The process of making something, or becoming, thick or viscous.
A substance, usually a source of starch, used to thicken a sauce.
A thickened part of a structure.
(RQ:Schuster Hepaticae V)

(..) the inner layer (of nearly equally large cells) lacks the regular semiannular or annular thickenings of most other leafy liverworts (..)

They disappear at once on slightly relaxing the air-pressure, whilst true incipient thickenings of the surface remain white and unpliably stiff.