Introductory
SPECIES: Corylus cornuta var. californica | California Hazel 



ABBREVIATION : 
CORCORC

SYNONYMS : 
   Corylus californica Rose
   Corylus rostrata var. californica A. DC.


SCS PLANT CODE : 
   COCOC


COMMON NAMES : 
   California hazel
   California hazelnut
   California filbert


TAXONOMY : 
The accepted scientific name for California hazel is Corylus cornuta
Marsh. var. californica (A. DC.) Sharp [15,27].  The genus Corylus
comprises 15 species, most of which occur in Asia.  Corylus cornuta is
the only species native to the United States [5,17].  Corylus cornuta is
distributed across North America.  Corylus cornuta var. californica is
the Pacific Coast entity of the species [5]; C. cornuta Marsh. var.
cornuta (beaked hazel) is a shrub occupying the eastern range of the
species [17].  There are two recognized forms of C. cornuta var.
californica [5]:

        C. cornuta var. californica forma californica
        C. cornuta var. californica forma glandulosa (Boivin)
                        stat.nov.(C. cornuta var. glandulosa Boivin).


LIFE FORM : 
Tree, Shrub

FEDERAL LEGAL STATUS : 
No special status

OTHER STATUS : 
NO-ENTRY


COMPILED BY AND DATE : 
Mary Lou Zimmerman, May 1991


LAST REVISED BY AND DATE : 
NO-ENTRY


AUTHORSHIP AND CITATION : 
Zimmerman, Mary Lou 1991.  Corylus cornuta var. californica.  In: Remainder of Citation

DISTRIBUTION AND OCCURRENCE
SPECIES: Corylus cornuta var. californica | California Hazel 



GENERAL DISTRIBUTION : 
California hazel occurs in California, Oregon, Washington, and British
Columbia [26].  In California it occurs along the Coast Range from Santa
Cruz County northward along the coast to Del Norte County, eastward
through Siskiyou County, and southward in the Sierra Nevada to Tulare
County [22].  In Oregon and Washington it occurs mostly west and
occasionally east of the Cascades [13].  In British Columbia it occurs
on the lower mainland and on Vancouver Island [12].

Intermediate forms of C. cornuta var. californica x C. cornuta var.
cornuta may occur in the Fraser Canyon and Columbia Forest Region of
British Columbia [5].

Corylus cornuta var. californica forma glandulosa is frequently found
along the Pacific Coast.  It is more frequent than C. cornuta var.
californica forma californica on southern Vancouver Island but becomes
scarcer inland [5].


ECOSYSTEMS : 
   FRES20  Douglas-fir
   FRES23  Fir - spruce
   FRES24  Hemlock - Sitka spruce
   FRES27  Redwood
   FRES28  Western hardwoods


STATES : 
     CA  OR  WA  BC


ADMINISTRATIVE UNITS : 
     CODA  CRLA  MORA  NOCA  OLYM  PORE
     REDW  WHIS


BLM PHYSIOGRAPHIC REGIONS : 
   1  Northern Pacific Border
   2  Cascade Mountains
   3  Southern Pacific Border
   4  Sierra Mountains


KUCHLER PLANT ASSOCIATIONS : 
   K001  Spruce - cedar - hemlock forest
   K002  Cedar - hemlock - Douglas-fir forest
   K003  Silver fir - Douglas-fir forest
   K005  Mixed conifer forest
   K006  Redwood forest
   K007  Red fir forest
   K012  Douglas-fir forest
   K026  Oregon oakwoods
   K028  Mosaic of K002 and K026
   K029  California mixed evergreen forest


SAF COVER TYPES : 
   211  White fir
   221  Red alder
   222  Black cottonwood - willow
   224  Western hemlock
   226  Coastal true fir - hemlock
   227  Western redcedar - western hemlock
   229  Pacific Douglas-fir
   230  Douglas-fir - western hemlock
   232  Redwood 
   233  Oregon white oak
   234  Douglas-fir - tanoak - Pacific madrone


SRM (RANGELAND) COVER TYPES : 
NO-ENTRY


HABITAT TYPES AND PLANT COMMUNITIES : 
Published classifications listing California hazel as a dominant in
plant associations (pas) or community types (cts) are presented below:

        Location              Classification     Authority

  OR:  Willamette Valley      forest cts         Thilenius  1968 
       c Cascades             forest pas, cts    Dyrness and others  1974
       Mary's Peak Watershed  forest cts         Anderson 1969
       Mary's Peak Watershed  forest cts         Anderson 1967  
s OR:  Cascade Mountain
       Province               forest pas         Atzet and McCrimmon 1990

VALUE AND USE
SPECIES: Corylus cornuta var. californica | California Hazel 



WOOD PRODUCTS VALUE : 



IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
In some localities, California hazel is browsed extensively by livestock
and wildlife; in others it is scarcely used.  Utilization depends on the
relative palatability and abundance of associated vegetation in a given
area [22,28].  In California, it is considered of slight importance as
browse for mule deer [28].  In western hemlock (Tsuga heterophylla)-red
alder (Alnus rubra) forests in Oregon and Washington, it provides good
big game browse [3].  Birds consume the buds and catkins [12].

Nuts of California hazel are a staple food of the Steller's Jay,
chickaree, Townsend's chipmunk, Allen's chipmunk, golden-mantled
squirrel, and digger squirrel [28].


PALATABILITY : 
The palatability of California hazel ranges from fair to poor for most
livestock and wildlife species [22,26].


NUTRITIONAL VALUE : 
NO-ENTRY


COVER VALUE : 
NO-ENTRY


VALUE FOR REHABILITATION OF DISTURBED SITES : 
California hazel is valuable as a soil binder on steep slopes [26].


OTHER USES AND VALUES : 
The edible nuts of California hazel have a sweet flavor and are commonly
collected [26].  The glandular hairs (spiculae) on the nut husk
(involucre) have been used as a remedy for parasitic intestinal worms
[26].  Native peoples used the slender 1- and 2-year-old twigs for
basket making [26].


MANAGEMENT CONSIDERATIONS : 
Beaked hazel has long been recognized as a major deterrent to the
successful regeneration of upland conifers [7].  Heavilin [14], however,
reported that California hazel shrubs up to 16 feet tall did not appear
to deter succsessful establishment and growth of Douglas-fir
(Psuedotsuga menziesii) seedlings planted under them.

Chemical application is an effective method for control of California
hazel.  Most herbicidal applications to this shrub result in good
top-kill; resulting root sprouts are less than one-third of the original
plant height after two growing seasons [24].

Heavy browsing by deer can stimulate beaked hazel to produce basal
sprouts or suckers.  A 1952 clipping experiment produced similar results
[12].  Total twig production was increased for 3 years under heavy
clipping, but thereafter began to decline.  Light clipping had little
impact on growth [12].  The response of California hazel to clipping
would probably be similar to that of beaked hazel.  California hazel,
however, does not have the ability to sprout from lateral root suckers.

BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Corylus cornuta var. californica | California Hazel 



GENERAL BOTANICAL CHARACTERISTICS : 
California hazel is an erect, deciduous, native, perennial shrub, or
occasionally small tree [17].  It is multistemmed and loosely spreading,
averaging 5 to 12 feet (1.5-4 m) in height.  It can exceed 20 feet (6 m)
in height and develop a treelike form with a singular trunk.  The bark
is smooth.  The twigs are brown, slender, and zigzagged.  The current
year's twigs are hairy.  Staminate flowers are borne in pedent catkins
on the previous year's twigs.  Pistillate fowers are borne singularly
from small rounded buds and have bright red stigmas.  The fruit is a
round, smooth nut with a very hard shell.  It is enclosed in a leafy sac
which protrudes beyond the nut like a beak and is covered with stiff
hairs.  These sacs are borne singularly, or in groups of two or three,
at the end of the current year's twigs.  [6,13,19,22,26,28]


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Sexual:  California hazel produces large seed crops at irregular
intervals, every 2 or 3 years to every 5 years [6,12].  Late frosts can
kill flowers, and dry weather can affect fertilization [12].  Seed
production increases with stem age, peaking at 10 or 11 years, and
ceasing when twigs are 18 years old [12].  Small mammals and birds are
the primary dispersal agents [6].
 
Seeds have poor viablity in storage and must remain moist.  Two to six
months of chilling is required before germination can take place [6].
Germination rates are low.  In laboratory tests, best results were
achieved when the nuts were covered with humus to prevent drying [12].
Mirov and Kraebel [18] obtained 20 percent germination from seed
stratified for 3 months in peat moss; seeds germinated 96 days after
sowing.  Seed survival is low due to animal predation.  Although only a
small number of nuts produce seedlings, in good seed years regeneration
by seed allows California hazel to to invade new sites [12].

Vegetative:  California hazel sprouts from the root crown after its
aerial crown has been removed [26].  It does not sprout from lateral
root suckers, as beaked hazel does [12].  California hazel also
regenerates by layering [12].


SITE CHARACTERISTICS : 
California hazel is typically found on moist and well-drained sites.  It
occurs on cool shaded sites on north-facing slopes, along streambanks,
in moist wooded canyons and slopes, in the understory of oak and conifer
forests, and in open, burned or cut-over lands [20,22,26,28].

Soil:  California hazel occurs on a variety of soils ranging from moist,
black loam to dry, stony soils, and even appears in crevices in rocks.
It is most abundant on the moderately fertile but stony soils of slopes,
on dry and rocky islands, and along streambanks [26].

Climate:  California hazel is adapted to a mild, temperate climate.  It
has lower frost resistance than beaked hazel [12].

Elevation:  In the coastal mountains of California and at the northern
edge of its range in British Columbia, California hazel occurs at low
elevations.  It occurs at increasingly higher elevations inland and at
its southern perimeter [12,22,26].  It generally occurs below 7,000 feet
(2,134 m) in California and from sea level to 2,625 feet (0-800 m) in
British Columbia.


SUCCESSIONAL STATUS : 
California hazel exhibits both tolerant and intolerant behavior.  It is
able to survive in the forest understory and to invade open sites.

In central Oregon, California hazel was found growing under crown
openings in a 36- to 40-year-old stand of Douglas-fir; it formed an even
shrub layer in a 20-year-old Douglas-fir plantation; and it was found
growing scattered over a recently clearcut unit [23].  In the Oregon
Cascades, California hazel has been listed as an invader of clearcut and
burned units of old-growth Douglas-fir (it was absent from the
undergrowth of adjacent uncut units) [29].


SEASONAL DEVELOPMENT : 
Male and female flower buds are formed in late summer and remain dormant
over the winter.  Fowers emerge in January to March before the leaves
appear [6,12,13,26].  Fruits develop by late summer or early fall [6]
and ripen from from September to October in California [6] and from
August to September in British Columbia [5].  In Oregon, vegetative buds
begin to swell in mid-March, three-quarters of the leaves are fully
developed by mid-June, and growth ceases in August [12].

FIRE ECOLOGY
SPECIES: Corylus cornuta var. californica | California Hazel 



FIRE ECOLOGY OR ADAPTATIONS : 
California hazel sprouts from the root crown after the aboveground
portion of the plant has been destroyed [26].


POSTFIRE REGENERATION STRATEGY : 
   Tall shrub, adventitious-bud root crown
   Initial-offsite colonizer (off-site, initial community)

FIRE EFFECTS
SPECIES: Corylus cornuta var. californica | California Hazel 



IMMEDIATE FIRE EFFECT ON PLANT : 
The aboveground parts of California hazel are easily killed by fire,
even by light spring fires [7,12].

Because of their moisture requirements, seeds probably do not survive
the high temperatures and drying associated with fire.


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
California hazel responds to spring fires by vigorous and abundant
sprouting; sprouting after summer fires is less vigorous [7].  Prefire
stature and density are regained in only a few years [12].


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
Fire would destroy California hazel only under the most extreme fuel and
weather conditions.  Repeated spring burning conducted when the soil is
moist simply increases the number of stems present [12].  However,
repeated summer fires destroy hazel's ability to sprout by exposing and
destroying underground root systems and exhausting stored food reserves
[7].

References for species: Corylus cornuta var. californica

1. Anderson, Howard George. 1967. The phytosociology of some vine maple communities in the Mary's Peak watershed. Corvallis, OR: Oregon State University. 118 p. Thesis. [9877]

2. Anderson, H. G. 1969. Growth form and distribution of vine maple (Acer circinatum) on Marys Peak, western Oregon. Ecology. 50(1): 127-130. [8425]

3. Atzet, Thomas; McCrimmon, Lisa A. 1990. Preliminary plant associations of the southern Oregon Cascade Mountain Province. Grants Pass, OR: U.S. Department of Agriculture, Forest Service, Siskiyou National Forest. 330 p. [12977]

4. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals, reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's associations for the eleven western states. Tech. Note 301. Denver, CO: U.S. Department of the Interior, Bureau of Land Management. 169 p. [434]

5. Brayshaw, T. Christopher. 1976. Catkin bearing plants of British Columbia. Occas. Pap. No. 18. Victoria, BC: The British Columbia Provincial Museum. 176 p. [6170]

6. Brinkman, Kenneth A. 1974. Corylus L. hazel, filbert. In: Schopmeyer, C. S., technical coordinator. Seeds of woody plants in the United States. Agric. Handb. 450. Washington, DC: U.S. Department of Agriculture, Forest Service: 343-345. [7594]

7. Buckman, Robert E. 1964. Effects of prescribed burning on hazel in Minnesota. Ecology. 45(3): 626-629. [12204]

8. Dyrness, C. T.; Franklin, J. F.; Moir, W. H. 1974. A preliminary classification of forest communities in the central portion of the western Cascades in Oregon. Bulletin No. 4. Seattle, WA: University of Washington, Ecosystem Analysis Studies, Coniferous Forest Biome. 123 p. [8480]

9. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905]

10. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others]. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. [998]

11. Gratkowski, H. 1975. Silvicultural use of herbicides in Pacific Northwest forests. Gen. Tech. Rep. PNW-37. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 44 p. [10998]

12. Haeussler, S.; Coates, D. 1986. Autecological characteristics of selected species that compete with conifers in British Columbia: a literature review. Land Management Report No. 33. Victoria, BC: Ministry of Forests, Information Services Branch. 180 p. [1055]

13. Hayes, Doris W.; Garrison, George A. 1960. Key to important woody plants of eastern Oregon and Washington. Agric. Handb. 148. Washington, DC: U.S. Department of Agriculture, Forest Service. 227 p. [1109]

14. Heavilin, Danny. 1977. Conifer regeneration on burned and unburned clearcuts on granitic soils of the Klamath National Forest. Res. Note PSW-321. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 3 p. [4981]

15. Kartesz, John T.; Kartesz, Rosemarie. 1980. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. Volume II: The biota of North America. Chapel Hill, NC: The University of North Carolina Press; in confederation with Anne H. Lindsey and C. Richie Bell, North Carolina Botanical Garden. 500 p. [6954]

16. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. [1384]

17. Little, Elbert L., Jr. 1979. Checklist of United States trees (native and naturalized). Agric. Handb. 541. Washington, DC: U.S. Department of Agriculture, Forest Service. 375 p. [2952]

18. Mirov, N. T.; Kraebel, C. J. 1937. Collecting and propagating the seeds of California wild plants. Res. Note No. 18. Berkeley, CA: U.S. Department of Agriculture, Forest Service, California Forest and Range Experiment Station. 27 p. [9787]

19. Mitchell, Rod; Moir, Will. 1976. Vegetation of the Abbott Creek Research Natural Area, Oregon. Northwest Science. 50(1): 42-58. [1664]

20. Munz, Philip A. 1973. A California flora and supplement. Berkeley, CA: University of California Press. 1905 p. [6155]

21. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843]

22. Sampson, Arthur W.; Jespersen, Beryl S. 1963. California range brushlands and browse plants. Berkeley, CA: University of California, Division of Agricultural Sciences, California Agricultural Experiment Station, Extension Service. 162 p. [3240]

23. Schoenberger, M. Meyer; Perry, D. A. 1982. The effect of soil disturbance on growth and ectomycorrhizae of Douglas- fir and western hemlock seedlings: a greenhouse bioassay. Canadian Journal of Forest Research. 12: 343-353. [12940]

24. Stewart, R. E. 1974. Foliage sprays for site preparation and release from six coastal brush species. Res. Pap. PNW-172. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 18 p. [11942]

25. Thilenius, John F. 1968. The Quercus garryana forests of the Willamette Valley, Oregon. Ecology. 49(6): 1124-1133. [8765]

26. U.S. Department of Agriculture, Forest Service. 1937. Range plant handbook. Washington, DC. 532 p. [2387]

27. U.S. Department of Agriculture, Soil Conservation Service. 1982. National list of scientific plant names. Vol. 1. List of plant names. SCS-TP-159. Washington, DC. 416 p. [11573]

28. Van Dersal, William R. 1938. Native woody plants of the United States, their erosion-control and wildlife values. Washington, DC: U.S. Department of Agriculture. 362 p. [4240]

29. Yerkes, Vern P. 1960. Occurrence of shrubs and herbaceous vegetation after clear cutting old-growth Douglas-fir. Res. Pap. PNW-34. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 12 p. [8937]

30. Zobel, Donald B.; Hawk, Glenn M.; McKee, W. Arthur; Dyrness, C. T. [n.d.]. Variation in plant moisture stress associated with forest communities in the H. J. Andrews Experimental Forest. U. S./International Biological Program, Ecosystem Analysis Studies, Coniferous Forest Biome. Seattle, Washington. 17. [10479]

Related categories for Species: Corylus cornuta var. californica | California Hazel