Terminology

Achene: A small, dry, 1-seeded fruit with a thin wall not prone to splitting (indehiscent).

Acuminate: Tapering gradually to a long slender point.

Alternate: Situated singly on a stem or placed regularly between organs of a different type (i.e., stamens alternate with sepals)

Bract: A reduced or modified leaf or leaf-like structure (or scale) at the base of a flower or inflorescence, or also a flower cluster.

Bracteole: A small bract, usually secondary in nature; a bractlet.

Bractlet: See Bracteole. 

Caudex: A short, persistent and often woody base of a herbacious perennial that is found at or just below the soil surface. It produces new growth annually, and often is found at the top of a rhizome or taproot. 

Cleft: Divided down to nearly the middle or base. 

Deciduous: Falling off at the completion of its function, as leaves from a tree; not evergreen; not persistent.

Moisture Regimes: Areas designated by moisture availability for plant growth. Factors influencing this include soil texture (internal drainage), slope (external drainage), local total precipitation amounts, soil surface conditions, and topographic position. The following moisture regime types are the following:

• Hydric: Saturated conditions, with water removal so slow that the water table remains at the soil surface.
• Sub-hydric: Soils wet to the extent that the permanent water table is near the surface for most of the year; discharge likely.
• Hygric: Soil remains moist for most of the growing season; permanent discharge areas.
• Sub-hygric: Water removal remains slow enough to prevent drying for extended periods throughout the growing season; precipitation and discharge water sources. 
• Mesic: Moderate water removal following precipitation, soil moisture generally persists for moderate time periods. 
• Sub-mesic: Moderately fast water removal following precipitation, soil moisture generally persists for moderate periods of time.
• Sub-xeric: Rapid water removal following precipitation, but soil moisture persists somewhat longer than in xeric conditions.
• Xeric: Water removal rapid, for brief periods soil is moist following precipitation
• Very-xeric: Very rapid water removal, soils remain dry most of the time following precipitation.

Plant communities: a complex array of unique combinations of plant species, usually of grasses, grass-likes, shrubs, and trees, and occasionally forbs. These combination compositions vary greatly from one location or ecoregion to another, with few dominating communities in the prairies, to more diverse communities in the foothills.