Hesperocyparis pigmaea Woodland Alliance
Mendocino pygmy cypress woodland

USDA Ecological Section Map

Summary Information

  • Primary Life FormTree
  • Elevation25-150 m
  • State RarityS1
  • Global RarityG1
  • DistributionUSA: CA (NatureServe) (Calflora)
  • Endemic to CaliforniaYes
  • Endemic to California Floristic Province and DesertsYes
  • Date Added1995/11/01

Characteristic Species

Hesperocyparis pigmaea is dominant or co-dominant in the tree canopy with Pinus contorta ssp. bolanderi, Pinus muricata and Sequoia sempervirens. Shrubs, which can be of heights similar to the cypress on oligotrophic soils, may include Arctostaphylos columbiana, Arctostaphylos nummularia, Gaultheria shallon, Rhododendron columbianum, Rhododendron macrophyllum or Vaccinium ovatum.

Vegetation Layers

Trees < 2 m; canopy of trees is open to intermittent. Shrub layer is open to intermittent. Herbaceous layer is sparse. Lichens and mosses occur on the soil surface and on the woody plants as epiphytes.

Membership Rules

  • Hesperocyparis pigmaea dominates the tree canopy (Westman 1975).
  • Hesperocyparis pigmaea > 30% relative cover in the tree canopy (VegCAMP 2018)


Uplifted marine terraces and associated sandstone. Soils are often acidic spodosols of the Blacklock soil series with cemented hardpans that are seasonally flooded.

Other Habitat, Alliance and Community Groupings

MCV (1995) Pygmy cypress series
NVCS (2009) Cupressus goveniana shrubland alliance
Calveg Pygmy cypress
Holland Mendocino pygmy cypress forest
Munz Closed-cone pine forest
WHR Closed-cone pine-cypress
CDFW CA Code 81.400.00

National Vegetation Classification Hierarchy

Formation Class Mesomorphic Tree Vegetation (Forest and Woodland)
Formation Subclass Temperate Forest
Formation Warm Temperate Forest
Division Madrean Forest and Woodland
Macro Group California Forest and Woodland
Group Californian evergreen coniferous forest and woodland