Definition: Organic matter in soil which has reached a point of stability, where it will break down no further and might, if conditions do not change, remain essentially as it is for centuries, or millennia.
Definition: Determined for type of life cycle being annual, binneal, perennial etc.
Comment: The life cycle habit indicates the typical duration of an individual plant's life. Common values are annual, biennial, and perennial. Some plants have different durations depending on environment or location, so a plant can have more than one value.
Definition: Of plant duration, a plant whose life span extends over more than two growing seasons, c.f. annual, biennial, ephemeral, of flowering with respect to architecture, hapaxanthic, monocarpic, pleonanthic