Jepson Flora Project: Jepson Interchange    

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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California
For up-to-date information about California vascular plants, visit the Jepson eFlora.



Dieter H. Wilken

Shrub, tree, generally monoecious
Leaves generally odd-1-pinnate, alternate, deciduous; stipules 0
Inflorescence: catkin, generally appearing before leaves, generally clustered; flowers generally solitary in bract axils
Staminate inflorescence generally pendent, generally elongate, generally many-flowered, on last year's twigs
Pistillate inflorescence generally erect; flowers 1–3, at tip of new twigs
Staminate flower: sepals 3–6; petals 0; stamens 3–many; pistil 0 or vestigial
Pistillate flower: sepals 3–6; petals 0; stamens 0; pistil 1, ovary inferior, chamber 1 above, generally 2 below, styles generally 2, plumose
Fruit: nut enclosed in a ± fleshy husk, drupe-like
Genera in family: 7 genera, ± 60 species: n temp, subtropical mtns; some ornamental, cultivated for wood, nuts (Carya hickory, pecan; Juglans )
Reference: [Elias 1972 J Arnold Arb 53:26–51]



Shrub, tree, generally monoecious
Stem generally erect; bark smooth to furrowed in age, gray to brown; twig centers chambered
Staminate flower: calyx lobes generally 4, ± fused to bract
Pistillate flower: calyx lobes 4, generally ± fused to bract and bractlets, with them forming husk in fruit
Fruit in clusters, generally spheric; husk leathery, strong-smelling, indehiscent yet ± deciduous
Species in genus: 21 species: temp North America., n temp Eur, Asia, South America
Etymology: (Latin: walnut)
Reference: [Howell 1973 Madroño 22:144]
Wood used for interior finishing, furniture; source of nuts.


J. californica S. Watson


Shrub, tree
Stem: trunks 1–5, generally < 25 m; bark gray to brown; twigs brown
Leaf: leaflets 11–19, 3–10 cm, lanceolate to ovate, toothed
Fruit (including husk) 2–3.5 cm diam; woody nut shell ± grooved
Ecology: Slopes, canyons, valleys
Elevation: 50–900 m.
Bioregional distribution: s Inner North Coast Ranges, s Sacramento Valley, n San Joaquin Valley, San Francisco Bay Area, Outer South Coast Ranges, South Coast, s Transverse Ranges, n Peninsular Ranges.Sometimes cultivated; hybrids with J. regia few, synthetic.


var. californica


Stem: trunks 1–5, generally < 15 m
Leaf: leaflets 2–8 cm
Fruit (including husk) generally 2–3 cm diam
Ecology: UNCOMMON. Slopes, canyons
Elevation: 50–900 m.
Bioregional distribution: Outer South Coast Ranges (Santa Lucia Mtns where perhaps cultivated), South Coast, s Transverse Ranges, Peninsular Ranges (Santa Ana Mtns)
Horticultural information: 4, 5, 6, 7, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, IRR: 8, 9, 10, 11.

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bioregional map for JUGLANS%20californica%20var.%20californica being generated
YOU CAN HELP US make sure that our distributional information is correct and current. If you know that a plant occurs in a wild, reproducing state in a Jepson bioregion NOT highlighted on the map, please contact us with that information. Please realize that we cannot incorporate range extensions without access to a voucher specimen, which should (ultimately) be deposited in an herbarium. You can send the pressed, dried collection (with complete locality information indicated) to us (e-mail us for details) or refer us to an accessioned herbarium specimen. Non-occurrence of a plant in an indicated area is difficult to document, but we will especially value your input on those types of possible errors (see automatic conversion of distribution data to maps).

Retrieve Jepson Interchange Index to Plant Names entry for Juglans californica var. californica
Retrieve dichotomous key for Juglans
Retrieve multiple-entry key (MEKA) for Juglans
Overlay Consortium of California Herbaria specimen data by county on this map
Show other taxa with the same California distribution | Read about bioregions | Get lists of plants in a bioregion
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