Terrestrial / Upland Humus forms or Semi-terrestrial / Aquatic
Humus forms
Substrate / Site poorly or very poorly drained, moisture regime > 5.
Mull L, Ah
Diagnostic organic horizons (F and H) lacking intimate association of colloidal organic matter with mineral substrate (well developed Ah).
Moder L, F, Hi, (Ah)
Hi horizon present, organic horizons not clearly delineated from mineral substrate.
Mor L, F, H
Hi horizon absent, organic horizons sharply delineated from mineral substrate.
Semi-terestrial or Aquatic Humus Forms
Of, Om, Oh present
Peaty Mor (L), (F), O(f, m, h)
Of, Om, Oh present
Fibric PeatyMor
Dominatly Of material
Mesic PeatyMor
Dominatly Om material
Humic PeatyMor