Physiognomy and Structure: Low-statured (<1.5 m) grassy meadows and "balds," often openings in otherwise shrubby forested slopes. Shrub and dwarf-shrubs may be imbedded in the grassland.

Floristics: Grasslands are the most prevalent vegetation cover. Dwarf-shrubs occur commonly, especially in mountains or foothills, as very small patches for the most part, usually in a matrix of herbaceous vegetation, most often near edges. Bunchgrasses often dominate and include Festuca rubra, Festuca idahoensis ssp. roemeri (= Festuca roemeri), or Danthonia californica. Other grasses that may be present include Achnatherum lemmonii, Agrostis spp., Aira caryophyllea, Bromus carinatus, Calamagrostis nutkaensis, Deschampsia cespitosa, Festuca idahoensis ssp. idahoensis, Holcus lanatus, Koeleria macrantha, or Trisetum canescens. Shrub and dwarf-shrub species imbedded in the herbaceous cover include Arctostaphylos uva-ursi, Arctostaphylos columbiana, Arctostaphylos nevadensis, Baccharis pilularis, Gaultheria shallon, Juniperus communis, Rosa nutkana, Symphoricarpos albus, and Vaccinium ovatum. Occasionally scattered stunted trees such as Picea sitchensis, Pseudotsuga menziesii, or Quercus garryana may be present. Perennial forbs may be present to abundant and include Allium cernuum, Camassia quamash, Camassia leichtlinii, Grindelia hirsutula, Iris douglasiana, Lomatium martindalei, Mimulus guttatus (in seeps), Plectritis congesta, Phlox diffusa, Sisyrinchium bellum, Sanicula arctopoides, and Triteleia hyacinthina. Significant portions of some balds, especially on rock outcrops, are dominated by bryophytes (mosses) such as Racomitrium canescens and to a lesser degree lichens (e.g., Cladonia portentosa (= Cladina portentosa)). The relative prevalence of grasslands versus shrublands increases from central to south range. To the north, conifers may occur more regularly. With fire suppression, Baccharis pilularis, Rosa nutkana, Symphoricarpos albus, and other shrubs may invade and can replace these grasslands with scrub-dominated systems. With increasing development activity, the invasive Cytisus scoparius may dominate the flora in the northern part of the range in British Columbia.

Dynamics:  These sites are naturally non-forested due to shallow soils, steep slopes, sunny aspect, and/or upper slope position, rendering them too dry and marginal for tree establishment and growth except in microsites. In the northern part of the range, in British Columbia, the major limiting factor on shrub and tree cover is drought. In the central and southern range, shrub encroachment was also controlled by lightning-caused wildfires and intentional burns by Native Americans, which were historically frequent. More populated areas along the coastline probably burned more frequently than remote areas. A shift away from Native American to European practices and active fire suppression over the last 150 years has allowed shrubs to encroach sites in some parts of the range, causing a decline in the south-central range of this macrogroup. In British Columbia, the major decline is due to human development. The introduced Cytisus scoparius is most problematic where it spreads from initial invasion along roaded areas, and into these dry non-wooded sites.