View source for Corylus ← Corylus You do not have permission to edit this page, for the following reason: The action you have requested is limited to users in the group: Users. You can view and copy the source of this page. {{Treatment/ID |accepted_name=Corylus |accepted_authority=Linnaeus |publications={{Treatment/Publication |title=Sp. Pl. |place=2: 998. 175 }}{{Treatment/Publication |title=Gen. Pl. ed. |place=5, 433. 1754 |year=1754 }} |common_names=Hazel |basionyms= |synonyms= |hierarchy=Betulaceae;Betulaceae subfam. Coryloideae;Corylus |hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Betulaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Betulaceae subfam. Coryloideae]]</div><div class="higher-taxon"><small>genus</small>[[Corylus]]</div></div> |etymology=Latin corylus, hazel, from Greek korus, helmet, for shape and hardness of nut shells |volume=Volume 3 |mention_page= |treatment_page= }}<!-- --><span class="statement" id="st-d0_s0" data-properties="shrub some measurement;tree some measurement"><b>Shrubs </b>and trees, 3–15 m;</span> <span class="statement" id="st-d0_s1" data-properties="trunk growth form;trunk quantity;trunk architecture;trunk architecture or texture;trunk shape;branch shape">tree trunks usually 1, branching mostly deliquescent, trunks and branches terete.</span> <span class="statement" id="st-d0_s2" data-properties="bark coloration;bark width;bark architecture or pubescence or relief;bark arrangement;strip orientation;scale orientation"><b>Bark </b>grayish brown, thin, smooth, close, breaking into vertical strips and scales in age;</span> <span class="statement" id="st-d0_s3" data-properties="lenticel prominence;lenticel presence">prominent lenticels absent.</span> <span class="statement" id="st-d0_s4" data-properties="wood coloration;wood coloration;wood coloration;wood texture;wood texture"><b>Wood </b>nearly white to light-brown, moderately hard, heavy, texture fine.</span> <span class="statement" id="st-d0_s5" data-properties="twig arrangement;twig density"><b>Branches,</b> branchlets, and twigs nearly 2-ranked to diffuse;</span> <span class="statement" id="st-d0_s6" data-properties="twig life cycle;twig variability;short-shoot length or size">young twigs differentiated into long and short-shoots.</span> <span class="statement" id="st-d0_s7" data-properties="bud season;bud architecture;bud shape;apex shape"><b>Winter </b>buds sessile, broadly ovoid, apex acute;</span> <span class="statement" id="st-d0_s8" data-properties="scale quantity;scale arrangement;scale architecture or pubescence or relief">scales several, imbricate, smooth.</span> <span class="statement" id="st-d0_s9" data-properties="leaf arrangement;short-shoot length or size"><b>Leaves </b>on long and short-shoots, 2-ranked.</span> <span class="statement" id="st-d0_s10" data-properties="leaf-blade shape;leaf-blade length;leaf-blade width;lateral-vein width;base shape;margin architecture or shape;apex shape"><b>Leaf-</b>blade broadly ovate with 8 or fewer pairs of lateral-veins, 4–12 × 3.5–12 cm, thin, bases often cordate, margins doubly serrate, apex occasionally nearly lobed;</span> <span class="statement" id="st-d0_s11" data-properties="surface pubescence;surface architecture or function or pubescence">surfaces abaxially usually pubescent, sometimes glandular.</span> <span class="statement" id="st-d0_s12" data-properties="catkin architecture;catkin prominence;catkin size;short-shoot position;season growth order"><b>Inflorescences:</b> staminate catkins on short-shoots lateral on branchlets, in numerous racemose clusters, formed previous growing season and exposed during winter, expanding well before leaves;</span> <span class="statement" id="st-d0_s13" data-properties="catkin architecture;catkin position or shape;catkin size;catkin architecture;style prominence;style size">pistillate catkins distal to staminate catkins, in small clusters of flowers and bracts, reduced, only styles protruding from buds containing them at anthesis, expanding at same time as staminate.</span> <span class="statement" id="st-d0_s14" data-properties="flower architecture;flower architecture or arrangement;catkin quantity"><b>Staminate </b>flowers in catkins 3 per scale, congested;</span> <span class="statement" id="st-d0_s15" data-properties="stamen quantity;stamen shape;base quantity">stamens 4, divided nearly to base to form 8 half-stamens;</span> <span class="statement" id="st-d0_s16" data-properties="filament height or length or size;filament fusion;bractlet quantity">filaments very short, adnate with 2 bractlets to bract.</span> <span class="statement" id="st-d0_s17" data-properties="flower architecture;flower quantity"><b>Pistillate </b>flowers 2 per bract.</span> <span class="statement" id="st-d0_s18" data-properties="infructescence architecture or arrangement;infructescence arrangement;fruit quantity;involucre position relational;beak quantity;beak pubescence;beak size;beak architecture;beak fusion;tube size"><b>Infructescences </b>compact clusters of several fruits, each subtended and surrounded by involucre of bracts, bracts 2, hairy [spiny], expanded, foliaceous, sometimes connate into short-to-elongate tube.</span> <span class="statement" id="st-d0_s19" data-properties="nut architecture"><b>Fruits </b>relatively thin-walled nuts, nearly globose to ovoid, somewhat laterally compressed, longitudinally ribbed.</span> <span class="statement" id="st-d0_s20" data-properties="fruit shape;fruit shape;fruit shape;fruit shape;fruit architecture or shape;x chromosome quantity">x = 11.</span><!-- -->{{Treatment/Body |distribution=Throughout north temperate zone;North America;Europe;Asia |discussion=<p>Species ca. 15 (3 in the flora).</p><!-- --><p>Corylus differs from other Betulaceae in various features, most notably in the infructescences, which consist of small clusters of well-developed nuts, each enclosed by a loose involucre of leaflike bracts. As in Ostrya, the staminate catkins are formed during the summer and are exposed through the winter prior to anthesis. In Corylus, however, pistillate catkins develop at the same time as the staminate, and they consist of only a few flowers, protected by the scales of special buds rather than being arranged in elongate pistillate catkins. The staminate flowers are unique in the family in that well-developed sepals are occasionally present, clearly defining the three individual flowers that make up each cymule.</p><!-- --><p>A longstanding disparity occurs in the literature regarding the diploid chromosome number found in Corylus species, with both 2n = 22 and 2n = 28 being cited. J. G. Packer (pers. comm.) believes that the 2n = 28 for several species (R. H. Woodworth 1929c) was in error because of a misinterpretation of Woodworth's meiotic preparations, a number of which actually indicate eleven haploid chromosomes. Woodworth's count may be largely, if not entirely responsible for the persistence of this number in the literature.</p><!-- --><p>The genus consists of three major subgroups, the first composed of shrubby plants having a short, open involucre of two bracts surrounding the fruits (Corylus sect. Corylus). Members of Corylus sect. Tuboavellana Spach are of similar habit but have the involucre modified into a tubular beak, and Corylus sect. Acanthochlamnys Spach is characterized by densely spiny bracts. Recent treatments have avoided applying sectional names. The genus as a whole should be considered for taxonomic revision.</p><!-- --><p>Corylus is the source of hazelnuts and filberts. Commercial filberts (C. colurna Linnaeus and C. maxima Miller) are cultivated in various parts of the world, particularly Turkey, Italy, Spain, China, and the United States. Wild hazelnuts (C. americana and C. cornuta) are smaller but similar in flavor to those of the cultivated species.</p> |tables= |references={{Treatment/Reference |id=drumke1965a |text=Drumke, J. S. 1965. A systematic survey of Corylus in North America. Diss. Abstr. 25: 4925--4926. }}{{Treatment/Reference |id=kasapligil1964a |text=Kasapligil, B. 1964. A contribution to the histotaxonomy of Corylus (Betulaceae). Adansonia, n. s. 4: 43--90. }}{{Treatment/Reference |id=rose1895a |text=Rose, J. N. 1895. Notes upon Corylus rostrata and C. californica. Gard. & Forest 8: 263. }}{{Treatment/Reference |id=wiegand1909a |text=Wiegand, K. M. 1909. Recognition of Corylus rostrata and Corylus americana. Rhodora 11: 107. }} }}<!-- --><div class="treatment-key"> ==Key== <div class="treatment-key-group"> {| class="wikitable fna-keytable" |-id=key-0-1 |1 |Fruit surrounded by soft bristly involucre connate to summit into narrow tube 2–5 times length of fruit; branchlets and petioles glabrous to pubescent, with or without glandular hairs. |[[Corylus cornuta|Corylus cornuta]] |-id=key-0-1 |1 |Fruit surrounded by involucre of 2 downy, expanded, foliaceous bracts, distinct nearly to base; branchlets and petioles covered with bristly glandular hairs. |[[#key-0-2| > 2]] |-id=key-0-2 |2 |Involucre slightly longer than to 2 times length of fruit; staminate catkins mostly in groups of 1–2, peduncles 5 mm or shorter; slender native shrubs to ca. 3 m. |[[Corylus americana|Corylus americana]] |-id=key-0-2 |2 |Involucre shorter than to only slightly longer than fruit; staminate catkins mostly in groups of 2–4, peduncles more than 5 mm; broad, spreading, introduced shrubs to ca. 5 m. |[[Corylus avellana|Corylus avellana]] |} </div></div><!-- -->{{#Taxon: name=Corylus |author= |authority=Linnaeus |rank=genus |parent rank=subfamily |synonyms= |basionyms= |family=Betulaceae |distribution=Throughout north temperate zone;North America;Europe;Asia |reference=drumke1965a;kasapligil1964a;rose1895a;wiegand1909a |publication title=Sp. Pl.;Gen. Pl. ed. |publication year=;1754 |special status= |source xml=https://jpend@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/287ef3db526bd807d435a3c7423ef2df1e951227/V3/V3_322.xml |subfamily=Betulaceae subfam. Coryloideae |genus=Corylus |apex shape=lobed;acute |bark architecture or pubescence or relief=smooth |bark arrangement=close |bark coloration=grayish brown |bark width=thin |base quantity=8 |base shape=cordate |beak architecture=foliaceous |beak fusion=connate |beak pubescence=hairy |beak quantity=2 |beak size=expanded |bractlet quantity=2 |branch shape=terete |bud architecture=sessile |bud season=winter |bud shape=ovoid |catkin architecture=staminate;pistillate;staminate |catkin position or shape=distal |catkin prominence=exposed |catkin quantity=3 |catkin size=reduced;expanding |filament fusion=adnate |filament height or length or size=short |flower architecture=pistillate;staminate |flower architecture or arrangement=congested |flower quantity=2 |fruit architecture or shape=ribbed |fruit quantity=several |fruit shape=compressed;nearly globose;ovoid |infructescence architecture or arrangement=compact |infructescence arrangement=cluster |involucre position relational=surrounded |lateral-vein width=3.5cm;12cm |leaf arrangement=2-ranked |leaf-blade length=4cm;12cm |leaf-blade shape=ovate |leaf-blade width=thin |lenticel presence=absent |lenticel prominence=prominent |margin architecture or shape=serrate |nut architecture=thin-walled |scale architecture or pubescence or relief=smooth |scale arrangement=imbricate |scale orientation=vertical |scale quantity=several |season growth order=previous |short-shoot length or size=long;long |short-shoot position=lateral |shrub some measurement=3m;15m |stamen quantity=4 |stamen shape=divided |strip orientation=vertical |style prominence=protruding |style size=expanding |surface architecture or function or pubescence=glandular |surface pubescence=pubescent |tree some measurement=3m;15m |trunk architecture=branching |trunk architecture or texture=deliquescent |trunk growth form=tree |trunk quantity=1 |trunk shape=terete |tube size=short-to-elongate |twig arrangement=2-ranked |twig density=diffuse |twig life cycle=young |twig variability=differentiated |wood coloration=nearly white;light-brown |wood texture=fine;hard |x chromosome quantity=11 }}<!-- -->[[Category:Treatment]][[Category:Betulaceae subfam. 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