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Juglans californica

Higher Taxonomy
Family: JuglandaceaeView DescriptionDichotomous Key

Habit: Shrub, tree; monoecious. Leaf: odd-(even-)1-pinnate, alternate, deciduous; stipules 0. Inflorescence: catkin, generally appearing before leaves, 1 or clustered; flowers generally 1 in bract axils. Staminate Inflorescence: pendent, elongate, many-flowered, on last year's twigs. Pistillate Inflorescence: erect; flowers 1--many, at tip of new twigs. Staminate Flower: calyx [0 or] lobes generally 4 [2, 6]; petals 0; stamens 3--40[50]; pistil 0 or vestigial. Pistillate Flower: calyx [0] or lobes 4; petals 0; stamens 0; ovary 1, inferior, chamber 1 above, generally 2 below, styles 2, plumose. Fruit: nut enclosed in husk or winged nutlets.
Genera In Family: 9 genera, > 60 species: northern temperate, subtropical mountains; some ornamental, cultivated for wood, nuts (Carya hickory, pecan; Juglans walnut). Note: In Carya, Juglans, husk included in fruit diam, even though derived from involucre, calyx, and therefore not technically part of fruit.
eFlora Treatment Author: Alan T. Whittemore
Scientific Editor: Thomas J. Rosatti.
Genus: JuglansView DescriptionDichotomous Key

Common Name: WALNUT
Stem: bark smooth to furrowed in age, gray to gray-brown; twig centers chambered; buds scaly. Pistillate Inflorescence: flowers 1--few; in fruit erect. Pistillate Flower: styles elongate. Fruit: 1--3 unwinged nuts per inflorescence; leathery husk enclosing, not separating from each nut, not splitting.
Species In Genus: 21 species: North America, temperate Asia, South America. Etymology: (Latin: Jove's nut) Note: Wood used for interior finishing, furniture; source of nuts, dye. Juglans nigra L., occasionally planted, resembles Juglans hindsii but has leaflets uniformly pubescent abaxially, nuts deeply grooved, coarsely warty.

Juglans californica S. Watson
Stem: trunk 6--9 m. Leaf: petiole 2--5 cm; leaflets (9)11--15(17), 4--9.5 cm, generally narrow-elliptic to -lance-elliptic (less often lanceolate), +- serrate, rounded to acute, abaxial vein axils glabrous. Fruit: 2--3.5 cm diam, nut shell thick, shallowly grooved.
Ecology: Hillsides and canyons; Elevation: 30--900 m. Bioregional Distribution: SCoRO (Santa Lucia Range where cult), SW (exc ChI, SnBr). Flowering Time: Mar--May
Unabridged Synonyms: Juglans californica S. Watson var. californica
eFlora Treatment Author: Alan T. Whittemore
Jepson Online Interchange
Listed on CNPS Rare Plant Inventory

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Next taxon: Juglans hindsii

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botanical illustration including Juglans californica


Citation for this treatment: Alan T. Whittemore 2017. Juglans californica, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on May 27, 2017.

Citation for the whole project: Jepson Flora Project (eds.) 2017. Jepson eFlora,, accessed on May 27, 2017.

Juglans californica
click for enlargement
© 2003 Michael Charters
Juglans californica
click for enlargement
© 2003 Michael Charters
Juglans californica
click for enlargement
© 2003 Michael Charters
Juglans californica
click for enlargement
© 2003 Michael Charters

More photos of Juglans californica in CalPhotos

Geographic subdivisions for Juglans californica:
SCoRO (Santa Lucia Range where cult), SW (exc ChI, SnBr).
Markers link to CCH specimen records. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues. Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
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.
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CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.