viscid

tarttuva, tarrautuva viscous Viscous; having a high viscosity.
sticky Sticky, slimy, or glutinous.
1906, O. Henry, s:The Furnished Room|The Furnished Room

They trod noiselessly upon a stair carpet that its own loom would have forsworn. It seemed to have become vegetable; to have degenerated in that rank, sunless air to lush lichen or spreading moss that grew in patches to the staircase and was viscid under the foot like organic matter.