View source for Juglans

{{Treatment/ID
|accepted_name=Juglans
|accepted_authority=Linnaeus
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=2: 997. 175
}}, {{Treatment/Publication
|title=Gen. Pl. ed.
|place=5, 431. 1754
|year=1754
}}
|common_names=Walnut;nogal
|basionyms=
|synonyms=
|hierarchy=Juglandaceae;Juglans
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Juglandaceae]]</div><div class="higher-taxon"><small>genus</small>[[Juglans]]</div></div>
|volume=Volume 3
|mention_page=
|treatment_page=
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole_organism some measurement;whole_organism growth form;whole_organism some measurement;whole_organism growth form"><b>Shrubs </b>or trees, 3-50 m.</span> <span class="statement" id="st-d0_s1" data-properties="bark coloration;bark architecture or pubescence or relief"><b>Bark </b>light to dark gray or gray-brown, smooth or split into ridges or plates.</span> <span class="statement" id="st-d0_s2" data-properties="twig coloration;twig shape;twig fragility or size;hair architecture or arrangement;hair architecture"><b>Twigs </b>purplish brown, terete, stout, sparsely to densely covered with glands and capitate-glandular hairs, sometimes also with scales or fasciculate hairs, early in season with multiradiate hairs;</span> <span class="statement" id="st-d0_s3" data-properties="leaf-scar shape;leaf-scar shape;leaf-scar size">leaf-scars triangular or 3-lobed, large;</span> <span class="statement" id="st-d0_s4" data-properties="pith architecture">pith chambered.</span> <span class="statement" id="st-d0_s5" data-properties="bud-scale arrangement or dehiscence;bud-scale pubescence"><b>Bud-</b>scales valvate, densely hirsute.</span> <span class="statement" id="st-d0_s6" data-properties="leaf architecture"><b>Leaves </b>usually odd, sometimes even-pinnate;</span> <span class="statement" id="st-d0_s7" data-properties="">petiole and rachis with indument as twigs.</span> <span class="statement" id="st-d0_s8" data-properties="leaflet quantity;leaflet architecture;leaflet architecture;leaflet odor;leaflet variability;median leaflet character;median leaflet size;median leaflet atypical length;median leaflet atypical length;median leaflet length;median leaflet width"><b>Leaflets </b>5-25, sessile or subsessile, often aromatic, uniform in size or median leaflets largest, (2.5-) 4.3-15 (-17.5) × 0.8-6.5 cm;</span> <span class="statement" id="st-d0_s9" data-properties="gland architecture;gland pubescence">surfaces usually with nonglandular hairs (simple and/or fasciculate), glandular-hairs, sessile glands, and/or scales, sometimes glabrous.</span> <span class="statement" id="st-d0_s10" data-properties="catkin architecture;catkin architecture or arrangement or growth form;catkin architecture"><b>Staminate </b>catkins solitary from 2d-year twigs, sessile;</span> <span class="statement" id="st-d0_s11" data-properties="stamen quantity;stamen pubescence;stamen pubescence">stamens 7-50 per flower, glabrous or pilose.</span> <span class="statement" id="st-d0_s12" data-properties="flower architecture;flower architecture or arrangement or growth form;flower architecture or arrangement or growth form"><b>Pistillate </b>flowers solitary or in terminal racemes.</span> <span class="statement" id="st-d0_s13" data-properties="fruits nut shape"><b>Fruits </b>nuts enclosed in husks, not compressed;</span> <span class="statement" id="st-d0_s14" data-properties="husk width;husk dehiscence">husks thick, indehiscent;</span> <span class="statement" id="st-d0_s15" data-properties="nut coloration;nut shape;nut shape;nut architecture;nut shape;nut relief;nut relief;nut relief;nut relief">nuts tan, neither compressed nor angled, grooved, ridged, rugulose, or smooth;</span> <span class="statement" id="st-d0_s16" data-properties="shell width">shells thick.</span> <span class="statement" id="st-d0_s17" data-properties=""><b>Seeds </b>sweet.</span> <span class="statement" id="st-d0_s18" data-properties="seed taste;x chromosome quantity">x = 16.</span><!--

-->{{Treatment/Body
|distribution=North America;Mexico;West Indies;Central America;South America;Eurasia
|discussion=<p>Species 21 (6 in the flora).</p><!--
--><p>Juglans is a very important source of edible nuts, dyes, and wood for cabinet work, furniture, and construction. Juglans regia Linnaeus, the walnut of commerce, is widely cultivated in California; it is easily distinguished from native species by its leaves with 5-11 broad, entire leaflets and nuts with thin rugulose shells, not grooved or ridged. Because of its sensitivity to native pathogens, J. regia is usually grown as stem-grafts on roots of native or hybrid walnuts (see discussion under J. hindsii). Occasional seedlings of J. regia have been reported from the vicinity of cultivated plants, but these seldom, if ever, live to maturity.</p><!--
--><p>The growth form, bark, and fruit are important taxonomically in Juglans, but these usually are not available on herbarium specimens. As with many woody plants, the first one or two leaves of the season (i.e., the lowermost leaves on the twig) are sometimes atypical in structure, having broader, blunter leaflets. The fasciculate hairs on the veins normally have more rays than those on the blade. In addition to the types of hairs described below, small multiradiate hairs are found on the immature twigs, petioles, rachises, and midribs. They are usually gone when the leaf is fully expanded, but they may persist for a short time afterwards.</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Fruits ellipsoid to ovoid or cylindric, surface of nut with ca. 8 high, narrow, longitudinal main ridges, with narrow, interrupted, longitudinal ridges or lamellae between main ridges; terminal buds 12–18 mm; distal edge of leaf scar straight, bordered by well-defined velvety ridge; white walnuts (Juglans sect. Trachyocaryon Dode ex Manning).
|[[Juglans cinerea|Juglans cinerea]]
|-id=key-0-1
|1
|Fruits globose, rarely ellipsoid, surface of nut smooth or longitudinally grooved; terminal buds 3–10 mm; distal edge of leaf scar notched, usually glabrous, sometimes velvety, never forming prominent velvety ridge; black walnuts (Juglans sect. Rhysocaryon Dode).
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Leaflets narrowly elliptic to lance-elliptic, apex rounded to acute; abaxial surface without tufts of hairs in vein axils; s California.
|[[Juglans californica|Juglans californica]]
|-id=key-0-2
|2
|Leaflets lanceolate to lance-ovate or narrowly triangular, apex acuminate (sometimes blunter on 1st leaf of season); abaxial surface with conspicuous tufts of fasciculate hairs in vein axils (except sometimes J. microcarpa); widespread but not in s California.
|[[#key-0-3| > 3]]
|-id=key-0-3
|3
|Leaflet blades glabrous, hairs confined to major veins; nuts smooth or nearly so; California.
|[[Juglans hindsii|Juglans hindsii]]
|-id=key-0-3
|3
|Leaflet blades and veins with hairs, at least abaxially (hairs of blade sometimes becoming sparse late in season); nuts longitudinally grooved; widespread but not in California.
|[[#key-0-4| > 4]]
|-id=key-0-4
|4
|Fruits 1.4–2.3 cm; nuts 1.1–1.7 cm; leaflets 0.8–1.1(–2.2) cm wide, with capitate-glandular hairs, nonglandular hairs limited to axils of proximal veins on abaxial surface; shrubs or trees 3–10 m.
|[[Juglans microcarpa|Juglans microcarpa]]
|-id=key-0-4
|4
|Fruits 2–8 cm; nuts 1.8–4 cm; leaflets 1.5–5.5 cm wide, with both glandular and nonglandular hairs abaxially; trees 5–50 m.
|[[#key-0-5| > 5]]
|-id=key-0-5
|5
|Fruits 2–3.5 cm, nuts longitudinally grooved, surface between grooves smooth; leaflets 9–15, adaxially with capitate-glandular hairs.
|[[Juglans major|Juglans major]]
|-id=key-0-5
|5
|Fruits 3.5–8 cm, nuts longitudinally grooved, surface between grooves coarsely warty; leaflets (9–)15–19(–23), adaxially glabrous except for scattered hairs on midrib.
|[[Juglans nigra|Juglans nigra]]
|}
</div></div><!--

-->{{#Taxon:
name=Juglans
|author=Alan T. Whittemore;Donald E. Stone
|authority=Linnaeus
|rank=genus
|parent rank=family
|synonyms=
|basionyms=
|family=Juglandaceae
|distribution=North America;Mexico;West Indies;Central America;South America;Eurasia
|reference=None
|publication title=Sp. Pl.;Gen. Pl. ed.
|publication year=;1754
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V3/V3_1074.xml
|genus=Juglans
|bark architecture or pubescence or relief=smooth
|bark coloration=light;dark gray or gray-brown
|bud-scale arrangement or dehiscence=valvate
|bud-scale pubescence=hirsute
|catkin architecture=sessile;staminate
|catkin architecture or arrangement or growth form=solitary
|flower architecture=pistillate
|flower architecture or arrangement or growth form=in terminal racemes;solitary
|fruits nut shape=not compressed
|gland architecture=sessile
|gland pubescence=glabrous
|hair architecture=multiradiate
|hair architecture or arrangement=fasciculate
|husk dehiscence=indehiscent
|husk width=thick
|leaf architecture=even-pinnate
|leaf-scar shape=3-lobed;triangular
|leaf-scar size=large
|leaflet architecture=subsessile;sessile
|leaflet odor=aromatic
|leaflet quantity=5;25
|leaflet variability=uniform
|median leaflet atypical length=15cm;17.5cm
|median leaflet character=size
|median leaflet length=4.3cm;15cm
|median leaflet size=largest
|median leaflet width=0.8cm;6.5cm
|nut architecture=grooved
|nut coloration=tan
|nut relief=smooth;rugulose;smooth;rugulose
|nut shape=ridged;angled;compressed
|pith architecture=chambered
|seed taste=sweet
|shell width=thick
|stamen pubescence=pilose;glabrous
|stamen quantity=7;50
|twig coloration=purplish brown
|twig fragility or size=stout
|twig shape=terete
|whole_organism growth form=tree;shrub
|whole_organism some measurement=3m;50m
|x chromosome quantity=16
}}<!--

-->[[Category:Treatment]][[Category:Juglandaceae]]