The note presents as a deeply earthy, damp, and distinctly musty aroma, often possessing a cool, almost clammy quality. It is fungal in nature, reminiscent of decaying organic matter, but distinct from pure rot. There's an underlying greenness, like wet leaves left in a dark, enclosed space, sometimes with a subtle, sour tang. It possesses a low-to-moderate projection, tending to cling to surfaces and permeate textiles, suggesting a persistent rather than effervescent character. Its longevity can be surprisingly tenacious, often lingering long after other more volatile notes have dissipated. Functionally, it is not a typical top, heart, or base note in isolation; rather, it's a specific accord or a facet introduced by certain molecules, usually contributing to the base or deep heart to convey an aged or naturalistic dampness. It lacks brightness or crispness, instead exuding a dense, heavy presence.