View source for Rhamnus

{{Treatment/ID
|accepted_name=Rhamnus
|accepted_authority=Linnaeus
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=1: 193. 1753
|year=1753
}}
|common_names=Buckthorn;nerprun
|basionyms=
|synonyms=
|hierarchy=Rhamnaceae;Rhamnus
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Rhamnaceae]]</div><div class="higher-taxon"><small>genus</small>[[Rhamnus]]</div></div>
|etymology=Greek rhamnos, prickly shrubs, such as buckthorn
|volume=Volume 12
|mention_page=page 43, 44, 46, 51, 52, 62, 70
|treatment_page=page 45
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole_organism orientation;whole_organism orientation;whole_organism architecture;whole_organism architecture;whole_organism growth form;whole_organism orientation;whole_organism orientation;whole_organism architecture;whole_organism architecture;whole_organism growth form"><b>Shrubs </b>or trees, erect or spreading, unarmed or armed with thorns;</span> <span class="statement" id="st-d0_s1" data-properties="bud-scale presence;bud pubescence">bud-scales present, buds glabrate.</span> <span class="statement" id="st-d0_s2" data-properties="leaf duration;leaf duration;leaf presence;short-shoot life cycle;short-shoot arrangement;short-shoot arrangement;short-shoot architecture or arrangement"><b>Leaves </b>deciduous or persistent, present at flowering, alternate or opposite to subopposite, sometimes fascicled on short-shoots;</span> <span class="statement" id="st-d0_s3" data-properties="">blade not gland-dotted;</span> <span class="statement" id="st-d0_s4" data-properties="blade coloration;blade architecture;secondary-vein orientation;secondary-vein arrangement">pinnately veined, secondary-veins arching, not parallel.</span> <span class="statement" id="st-d0_s5" data-properties="inflorescence position;inflorescence arrangement;flower architecture or arrangement or growth form"><b>Inflorescences </b>axillary, within foliage, fascicles or cymes, or flowers solitary;</span> <span class="statement" id="st-d0_s6" data-properties="peduncle texture;pedicel texture">peduncles and pedicels not fleshy in fruit.</span> <span class="statement" id="st-d0_s7" data-properties="pedicel presence"><b>Pedicels </b>present.</span> <span class="statement" id="st-d0_s8" data-properties="flower reproduction;flower reproduction"><b>Flowers </b>usually unisexual, rarely some bisexual (plants polygamous);</span> <span class="statement" id="st-d0_s9" data-properties="hypanthium shape;hypanthium width;hypanthium dehiscence;proximal position">hypanthium campanulate to cupulate, 2–3 mm wide, usually not circumscissile, rarely so at or just proximal to sepal bases;</span> <span class="statement" id="st-d0_s10" data-properties="sepal quantity;sepal orientation;sepal coloration;sepal coloration;sepal coloration;sepal coloration;sepal shape;sepal width;sepal shape;sepal shape">sepals 4–5, spreading, yellowish, yellowish green, green, or greenish white to white, ovate-triangular, thin, not keeled or crested adaxially;</span> <span class="statement" id="st-d0_s11" data-properties="petal presence;petal atypical quantity;petal quantity;petal coloration;petal architecture;petal shape;petal shape">petals 0 or 4 [–5], yellowish to cream, hooded, spatulate, not clawed;</span> <span class="statement" id="st-d0_s12" data-properties="nectary width">nectary thin, lining hypanthium;</span> <span class="statement" id="st-d0_s13" data-properties="stamen quantity">stamens 4–5, (rudimentary in pistillate flowers);</span> <span class="statement" id="st-d0_s14" data-properties="ovary position;ovary architecture or structure in adjective form">ovary superior, 2–4-locular;</span> <span class="statement" id="st-d0_s15" data-properties="style quantity;style fusion">styles 2–4, connate proximally.</span> <span class="statement" id="st-d0_s16" data-properties=""><b>Fruits </b>drupes;</span> <span class="statement" id="st-d0_s17" data-properties="stone quantity;stone dehiscence">stones 2–4, longitudinally dehiscent.</span> <span class="statement" id="st-d0_s18" data-properties=""><b>Seeds </b>obovoid or oblong-obovoid, not beaked, longitudinally furrowed.</span> <span class="statement" id="st-d0_s19" data-properties="seed shape;seed shape;seed architecture or shape;seed architecture;x chromosome quantity">x = 12.</span><!--

-->{{Treatment/Body
|distribution=North America;Mexico;Central America;South America;Europe;e Asia;Africa
|discussion=<p>Species ca. 150 (14 in the flora).</p><!--
--><p>Rhamnus in the flora area includes six species (species 9–14) introduced primarily from Europe and Asia. The native species for the most part are clearly delimited, but the R. crocea complex needs taxonomic study using modern techniques.</p>
|tables=
|references={{Treatment/Reference
|id=johnston1975a
|text=Johnston, L. A. 1975. Revision of the Rhamnus serrata complex. Sida 6: 67–79.
}}{{Treatment/Reference
|id=wolf1938a
|text=Wolf, C. B. 1938. The North American species of Rhamnus. Rancho Santa Ana Bot. Gard. Monogr., Bot. Ser. 1.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Leaves persistent, alternate, blades distinctly coriaceous; petals 0 (rarely 4 in R. pilosa).
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Leaf blade secondary veins with basal pair diverging much more acutely than distal pairs; inflorescences cymes or flowers solitary; sepals 5; drupes dark red, becoming black, stones 3.
|[[Rhamnus alaternus|Rhamnus alaternus]]
|-id=key-0-2
|2
|Leaf blade secondary veins all diverging at nearly same angle; inflorescences fascicles or flowers solitary; sepals 4(–5); drupes red, stones 2.
|[[#key-0-3| > 3]]
|-id=key-0-3
|3
|Leaf blade margins entire or coarsely serrate, blunt-serrate, or spinulose-serrate.
|[[#key-0-4| > 4]]
|-id=key-0-4
|4
|Shrubs, 1.2–2(–4) m, usually armed with thorns; leaf blades 0.7–2 cm, elliptic to obovate or ovate; California mainland.
|[[Rhamnus crocea|Rhamnus crocea]]
|-id=key-0-4
|4
|Shrubs or trees, 2.5–6(–10) m, unarmed; leaf blades (1.5–)2–5(–6) cm, broadly elliptic to oblong or ovate-oblong; California Channel Islands.
|[[Rhamnus pirifolia|Rhamnus pirifolia]]
|-id=key-0-3
|3
|Leaf blade margins spinulose to spinose-dentate.
|[[#key-0-5| > 5]]
|-id=key-0-5
|5
|Branchlets stiff, glabrous or densely and softly hirtellous; both leaf blade surfaces glabrous.
|[[Rhamnus ilicifolia|Rhamnus ilicifolia]]
|-id=key-0-5
|5
|Branchlets flexible, sparsely to densely softly hirtellous; both leaf blade surfaces sparsely to densely softly hirtellous.
|[[Rhamnus pilosa|Rhamnus pilosa]]
|-id=key-0-1
|1
|Leaves deciduous, alternate, subopposite, or opposite, sometimes fascicled on short shoots, blades herbaceous to subcoriaceous; petals 0 or 4.
|[[#key-0-6| > 6]]
|-id=key-0-6
|6
|Leaves usually alternate, sometimes subopposite, blade secondary veins 4–11 pairs; shrubs or small trees 0.5–3(–4) m, unarmed.
|[[#key-0-7| > 7]]
|-id=key-0-7
|7
|Sepals 5; petals 0; drupe stones 3; shrubs 0.5–1(–1.5) m; wetlands and seeps.
|[[Rhamnus alnifolia|Rhamnus alnifolia]]
|-id=key-0-7
|7
|Sepals 4; petals 4; drupe stones 2 (3 in R. arguta); shrubs or small trees 0.5–3(–4) m; drier habitats.
|[[#key-0-8| > 8]]
|-id=key-0-8
|8
|Petioles 10–28 mm; pedicels 10–24(–30) mm; drupe stones 3; leaf blades usually broadly ovate, ovate, oblong-ovate, or ovate-cordate, sometimes ovate-orbiculate, margins spinulose-serrate.
|[[Rhamnus arguta|Rhamnus arguta]]
|-id=key-0-8
|8
|Petioles 3–8 mm; pedicels (0–)0.5–4 mm; drupe stones 2; leaf blades lanceolate, elliptic-lanceolate, oblong-lanceolate, elliptic, or elliptic-oblong, margins crenulate, crenulate-serrate, or serrulate.
|[[#key-0-9| > 9]]
|-id=key-0-9
|9
|Branchlets 6+ cm; leaf blade apices acute to acuminate; c, e United States.
|[[Rhamnus lanceolata|Rhamnus lanceolata]]
|-id=key-0-9
|9
|Branchlets 2–5 cm; leaf blade apices acute to obtuse or rounded; w United States.
|[[#key-0-10| > 10]]
|-id=key-0-10
|10
|Bud scales thin, glossy, pale golden to yellowish; leaf blades usually lanceolate, sometimes elliptic-lanceolate or oblong-lanceolate, 3–8 cm, both surfaces glabrous.
|[[Rhamnus smithii|Rhamnus smithii]]
|-id=key-0-10
|10
|Bud scales coriaceous, dull, dark red to reddish brown; leaf blades usually elliptic to elliptic-lanceolate or elliptic-oblong, 1.5–5(–5.5) cm, both surfaces minutely hirtellous.
|[[Rhamnus serrata|Rhamnus serrata]]
|-id=key-0-6
|6
|Leaves usually opposite to subopposite, sometimes alternate or fascicled on short shoots, blade secondary veins 2–7(–8) pairs; shrubs or trees (1–)2–10 m, armed with thorns.
|[[#key-0-11| > 11]]
|-id=key-0-11
|11
|Leaf blade bases rounded to truncate or cordate; drupe stones 3–4.
|[[#key-0-12| > 12]]
|-id=key-0-12
|12
|Leaf blade margins crenate-serrate, secondary veins 2–4 pairs; pedicels 2–4 mm; drupes 5–6(–8) mm.
|[[Rhamnus cathartica|Rhamnus cathartica]]
|-id=key-0-12
|12
|Leaf blade margins spinulose-serrate, secondary veins (3–)4–5 pairs; pedicels 10–24(–30) mm; drupes 7–10 mm.
|[[Rhamnus arguta|Rhamnus arguta]]
|-id=key-0-11
|11
|Leaf blade bases cuneate or acute; drupe stones 2.
|[[#key-0-13| > 13]]
|-id=key-0-13
|13
|Leaf blades obovate to elliptic-oblanceolate or broadly oblanceolate, adaxial surfaces usually minutely hirtellous at least along main veins on distal 1/3, rarely glabrous.
|[[Rhamnus japonica|Rhamnus japonica]]
|-id=key-0-13
|13
|Leaf blades usually elliptic to oblong, oblong-obovate, obovate-elliptic, or oblong-lanceolate, sometimes ovate to obovate, rarely oblanceolate-elliptic, adaxial surfaces glabrous or sparsely pilose on veins.
|[[#key-0-14| > 14]]
|-id=key-0-14
|14
|Leaf blades green abaxially, abaxial surface with straight, colorless hairs on veins, secondary veins 3–5(–6) pairs; pedicels 10–20 mm.
|[[Rhamnus davurica|Rhamnus davurica]]
|-id=key-0-14
|14
|Leaf blades yellowish green abaxially, abaxial surface with wavy or curled, yellow hairs along veins or at least in vein axils, secondary veins (4–)5–7(–8) pairs; pedicels 5–10 mm.
|[[Rhamnus utilis|Rhamnus utilis]]
|}
</div></div><!--

-->{{#Taxon:
name=Rhamnus
|author=Guy L. Nesom;John O. Sawyer†
|authority=Linnaeus
|rank=genus
|parent rank=family
|synonyms=
|basionyms=
|family=Rhamnaceae
|distribution=North America;Mexico;Central America;South America;Europe;e Asia;Africa
|reference=johnston1975a;wolf1938a
|publication title=Sp. Pl.
|publication year=1753
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V12/V12_820.xml
|genus=Rhamnus
|blade architecture=veined
|blade coloration=not gland-dotted
|bud pubescence=glabrate
|bud-scale presence=absent
|flower architecture or arrangement or growth form=solitary
|flower reproduction=bisexual;unisexual
|hypanthium dehiscence=circumscissile
|hypanthium shape=campanulate;cupulate
|hypanthium width=2mm;3mm
|inflorescence arrangement=fascicles
|inflorescence position=axillary
|leaf duration=persistent;deciduous
|leaf presence=absent
|nectary width=thin
|ovary architecture or structure in adjective form=2-4-locular
|ovary position=superior
|pedicel presence=absent
|pedicel texture=not fleshy
|peduncle texture=not fleshy
|petal architecture=hooded
|petal atypical quantity=4;5
|petal coloration=yellowish;cream
|petal presence=absent
|petal quantity=4
|petal shape=not clawed;spatulate
|proximal position=proximal
|secondary-vein arrangement=not parallel
|secondary-vein orientation=arching
|seed architecture=furrowed
|seed architecture or shape=not beaked
|seed shape=oblong-obovoid;obovoid
|sepal coloration=greenish white;white
|sepal orientation=spreading
|sepal quantity=4;5
|sepal shape=crested;not keeled;ovate-triangular
|sepal width=thin
|short-shoot architecture or arrangement=fascicled
|short-shoot arrangement=opposite;subopposite
|short-shoot life cycle=flowering
|stamen quantity=4;5
|stone dehiscence=dehiscent
|stone quantity=2;4
|style fusion=connate
|style quantity=2;4
|whole_organism architecture=armed;unarmed;armed;unarmed
|whole_organism growth form=tree;shrub
|whole_organism orientation=spreading;erect;spreading;erect
|x chromosome quantity=12
}}<!--

-->[[Category:Treatment]][[Category:Rhamnaceae]]