Trifolium variegatum Herbaceous Alliance
White-tip clover swales

USDA Ecological Section Map

Summary Information

  • Primary Life FormHerb
  • Elevation50-1000 m
  • State RarityS3?
  • Global RarityG3?
  • DistributionCAN: BC. USA: CA, OR, WA (NatureServe)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsNo
  • Date Added2009/09/01

Characteristic Species

Trifolium variegatum is dominant or characteristically present in the herbaceous layer with Aira caryophyllea, Avena barbata, Briza minor, Bromus diandrus, Bromus hordeaceus, Castilleja attenuata, Deschampsia danthonioides, Erodium botrys, Erodium cicutarium, Hedypnois cretica, Hesperevax caulescens, Hypochaeris glabra, Juncus bufonius, Leontodon saxatilis, Lolium perenne, Microseris elegans, Mimulus guttatus, Montia fontana, Soliva sessilis, Trifolium gracilentum, Trifolium microcephalum, Triphysaria eriantha and Vulpia bromoides.

Vegetation Layers

Herbs < 50 cm; cover is intermittent to continuous.

Membership Rules

  • Trifolium variegatum is conspicuous (average cover > 10%, but depending on season may be merely present) in the early to mid-spring growing season in the herbaceous layer; often growing with equally conspicuous cover of non-natives such as Hypochaeris glabra, Leontodon taraxacoides, Lolium perenne, and Vulpia bromoides (Klein et al. 2007).
  • Trifolium variegatum > 50% relative cover, or > 30% relative cover in the herbaceous layer with a variety of other native and non-native herbs such as Bromus spp., Juncus bufonius, Lolium perenne, Lotus spp., Plagiobothrys spp., Trifolium fucatum, and others (Buck-Diaz et al. 2021, Sikes et al. 2023).


Vernally moist edges of pools, swales, and seeps. Soils are sandy to clay or clay loam, generally fine grained. The USFWS Wetland Inventory (1996 national list) recognizes Trifolium variegatum as a FACW- plant.

Other Habitat, Alliance and Community Groupings

MCV (1995) California annual grassland series, Northern basalt flow vernal pool habitat, Northern hardpan vernal pool habitat
NVCS (2009) North Pacific hardpan vernal pool, Northern California volcanic vernal pool
Calveg Wet grasses and forbs, Vernal pool
Holland Valley and foothill grassland, Native grassland, Wildflower field, Freshwater seep
Munz Freshwater marsh, Valley grassland
WHR Annual grassland, Wet meadow
CDFW CA Code 42.005.00

National Vegetation Classification Hierarchy

Formation Class Mesomorphic Shrub and Herb Vegetation (Shrubland and Grassland)
Formation Subclass Temperate and Boreal Shrubland and Grassland
Formation Temperate and Boreal Freshwater Marsh
Division Western North American Freshwater Marsh
Macro Group Western North America Vernal Pool
Group Californian mixed annual/perennial freshwater vernal pool / swale bottomland