Jepson eFlora: Taxon page
Vascular Plants of California
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Corylus cornuta subsp. californica

Higher Taxonomy
Family: BetulaceaeView DescriptionDichotomous Key
Habit: Shrub, tree; monoecious. Stem: trunk < 35 m; bark smooth to scaly, peeling in thin layers or not, lenticels present or not. Leaf: simple, alternate, petioled, deciduous; stipules deciduous; blade ovate to elliptic, generally serrate, generally +- doubly so. Inflorescence: catkin, generally appearing before leaves, often clustered; bracts each subtending 2--3 flowers, 3--6 bractlets. Staminate Inflorescence: pendent, +- elongate. Pistillate Inflorescence: pendent or erect, developing variously in fruit (see key to genera). Staminate Flower: sepals 0--4, minute; petals 0; stamens 1--10; pistil vestigial or 0. Pistillate Flower: sepals 0--4; petals 0; stamens 0; pistil 1, ovary inferior or superior, chambers 2, each 1-ovuled by abortion, stigmas 2. Fruit: achene, nut, winged or not, subtended or enclosed by 1--2 bracts.
Genera In Family: 6 genera, 155 species: generally northern hemisphere; some cultivated.
eFlora Treatment Author: John O. Sawyer, Jr.
Scientific Editor: Thomas J. Rosatti.
Genus: CorylusView Description 

Common Name: HAZELNUT
Habit: Shrub, small tree. Stem: trunk < 6 m; bark smooth or scaly, dark brown; twigs glandular-hairy, becoming glabrous, brown; lenticels small; winter buds ciliate. Leaf: hairy; blade 4--10 cm, oblong to ovate, base oblique-cordate. Staminate Inflorescence: 4--7 cm; bracts each subtending 3 flowers, 3 bractlets. Pistillate Inflorescence: < 1 cm, appearing as terminal bud; bracts each subtending 2 flowers, 6 bractlets. Staminate Flower: sepals 0; stamens 4. Pistillate Flower: sepals 4; stigmas showy, red. Fruit: 1--2 per catkin, each enclosed in a papery involucre of 2 fused bracts, not winged.
Species In Genus: 15 species: northern hemisphere. Etymology: (Latin: hazelnut, filbert) Note: Flexible stems used in basket-making; some cultivated as food crop.
Reference: Furlow 1997 Syst Bot 26:283--298
Corylus cornuta Marshall subsp. californica (A. DC.) E. Murray
Stem: trunks < 4 m. Leaf: petiole 5--10 mm; blade +- velvety-hairy, base cordate, tip acute to acuminate. Fruit: 2--3 cm, involucre vase-shaped.
Ecology: Common. Many habitats, especially moist, shady places; Elevation: < 2100 m. Bioregional Distribution: NW, CaR, SN, CCo, SnFrB; Distribution Outside California: to British Columbia. Flowering Time: Jan--Mar
Synonyms: Corylus californica (A.DC.) Rose; Corylus cornuta var. californica (A.DC.) Sharp; Corylus rostrata Aiton var. tracyi Jeps.
Jepson eFlora Author: John O. Sawyer, Jr.
Reference: Furlow 1997 Syst Bot 26:283--298
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

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Botanical illustration including Corylus cornuta subsp. californica

botanical illustration including Corylus cornuta subsp. californica


Citation for this treatment: John O. Sawyer, Jr. 2012, Corylus cornuta subsp. californica, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on April 20, 2021.

Citation for the whole project: Jepson Flora Project (eds.) 2021, Jepson eFlora,, accessed on April 20, 2021.

Corylus cornuta subsp. californica
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© 2008 Neal Kramer
Corylus cornuta subsp. californica
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© 2010 Barry Breckling
Corylus cornuta subsp. californica
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© 2008 Neal Kramer
Corylus cornuta subsp. californica
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© 2002 Tony Morosco
Corylus cornuta subsp. californica
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© 2016 Steve Matson
Corylus cornuta subsp. californica
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© 2017 Steve Matson

More photos of Corylus cornuta subsp. californica in CalPhotos

Geographic subdivisions for Corylus cornuta subsp. californica:
NW, CaR, SN, CCo, SnFrB
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map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).


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Data provided by the participants of the  Consortium of California Herbaria.
View all CCH records
All markers link to CCH specimen records. The original determination is shown in the popup window.
Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.

CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time (fruiting time in some monocot genera).