View source for Ceanothus ← Ceanothus 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=Ceanothus |accepted_authority=Linnaeus |publications={{Treatment/Publication |title=Sp. Pl. |place=1: 195. 1753 |year=1753 }} |basionyms= |synonyms= |hierarchy=Rhamnaceae;Ceanothus |hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Rhamnaceae]]</div><div class="higher-taxon"><small>genus</small>[[Ceanothus]]</div></div> |etymology=Greek keanothus, name used by Dioscorides for some spiny plant |volume=Volume 12 |mention_page=page 43, 44, 78, 84, 89, 94, 107 |treatment_page=page 77 }}<!-- --><span class="statement" id="st-d0_s0" data-properties="whole_organism architecture;whole_organism architecture;whole_organism growth form"><b>Shrubs,</b> rarely arborescent, armed with thorns or unarmed;</span> <span class="statement" id="st-d0_s1" data-properties="bud-scale presence">bud-scales present.</span> <span class="statement" id="st-d0_s2" data-properties="leaf duration;leaf duration;leaf arrangement;leaf arrangement;leaf architecture or arrangement"><b>Leaves </b>persistent or deciduous, alternate or opposite, 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;blade architecture">pinnately veined or 3-veined from base (acrodromous).</span> <span class="statement" id="st-d0_s5" data-properties="inflorescence position;inflorescence position;cyme arrangement;cyme arrangement;thyrse shape;thyrse shape"><b>Inflorescences </b>terminal or axillary, cymes aggregated into umbellike clusters, or latter aggregated into racemelike or paniclelike thyrses;</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"><b>Flowers </b>bisexual;</span> <span class="statement" id="st-d0_s9" data-properties="hypanthium shape;hypanthium width">hypanthium shallowly cupulate to hemispheric, less than 0.5 mm wide;</span> <span class="statement" id="st-d0_s10" data-properties="sepal quantity;sepal atypical quantity;sepal atypical quantity;sepal quantity;sepal orientation;sepal orientation;sepal coloration;sepal coloration;sepal coloration;sepal coloration;sepal shape;sepal shape">sepals 5 (or (5–) 6 (–8) in C. jepsonii), usually incurved, sometimes becoming spreading, usually white to cream, blue, or purple, rarely pink, lanceolate to deltate, keeled adaxially;</span> <span class="statement" id="st-d0_s11" data-properties="petal quantity;petal atypical quantity;petal atypical quantity;petal quantity;petal coloration;petal coloration;petal coloration;petal coloration;petal architecture;petal shape;petal shape;petal shape">petals 5 (or (5–) 6 (–8) in C. jepsonii), usually white to cream, blue, or purple, rarely pink, hooded, spatulate or obovate, clawed;</span> <span class="statement" id="st-d0_s12" data-properties="nectary texture;nectary fusion">nectary fleshy, free from hypanthium;</span> <span class="statement" id="st-d0_s13" data-properties="stamen atypical quantity;stamen quantity">stamens 6 (–8);</span> <span class="statement" id="st-d0_s14" data-properties="ovary architecture or structure in adjective form">ovary 1/2-inferior, 3-locular;</span> <span class="statement" id="st-d0_s15" data-properties="style quantity;style fusion">styles 3 (sometimes 4 in C. jepsonii), connate basally.</span> <span class="statement" id="st-d0_s16" data-properties=""><b>Fruits </b>capsules, leathery exocarp sloughing off prior to dehiscence.</span> <span class="statement" id="st-d0_s17" data-properties="exocarp texture;x chromosome quantity">x = 12.</span><!-- -->{{Treatment/Body |distribution=North America;Mexico;Central America (Costa Rica);Central America (Guatemala);Central America (Panama) |discussion=<p>Species 58 (51 in the flora).</p><!-- --><p>Among the Ceanothus species found in the flora area, only three occur entirely east of the Rocky Mountains. Among the remaining species, a few of which are widespread in western North America, 42 are endemic to the California Floristic Province. Four species are entirely restricted to ultramafic (serpentine, gabbro) soils, while others occur on a diversity of substrates. Several widespread species are co-dominant shrubs in chaparral, or are important understory shrubs in woodlands and forests, especially in western North America. In addition to reproduction by seeds, many species of subgenus Ceanothus respond to fire by developing sprouts from the root crown, whereas all species in subgenus Cerastes reproduce strictly from seeds (F. I. Pugnaire et al. 2006). Many species form mycorrhizal associations (subterranean coralloid root clusters) with actinomycete symbionts (Frankia) and thus are capable of nitrogen fixation (S. L. Rose 1980; S. G. Conard et al. 1985).</p><!-- --><p>Hybridization is widespread in the genus, with at least 44 interspecific combinations reported in the literature (H. McMinn 1944; D. Fross and D. H. Wilken 2006), resulting from a common diploid chromosome number of 2n = 24 and the absence of strong isolating mechanisms. At least one putative hybrid swarm has been documented to include four species, Ceanothus cuneatus, C. divergens, C. gloriosus, and C. sonomensis (J. T. Howell 1940; M. A. Nobs 1963). The widespread occurrence of some hybrids often contributes to difficulty in identifying specimens, and in some cases may have contributed to complex local and regional patterns of variation in flower color or leaf morphology. Most hybrids are between taxa within the same subgenus. Intersubgeneric hybrids are few, and characterized by high levels of sterility. Ceanothus is a popular source of horticultural cultivars, with over 200 named selections (Fross and Wilken). One of the first and most popular hybrids in the 1830s was C. ×delilianus Spach, which was developed in France from a cross between C. americanus (eastern North America) and C. caeruleus Lagasca (Mexico).</p><!-- --><p>Some species and varieties of Ceanothus are considered difficult to identify. Some identification problems result from both local and geographical variation within species and intergradation following hybridization (M. Van Rensselaer and H. McMinn 1942; M. A. Nobs 1963). The dependence on both flower color and mature fruit morphology for accurate identification is exacerbated by a delay in fruit maturation following a short duration of flowering. Careful attention to life form, flower color, and fruit morphology is critical to identification. Knowledge of geographic distribution and edaphic substrate preference, especially in the California Floristic Province, can be helpful in determining a number of species.</p><!-- --><p>In the keys and descriptions that follow, tooth number is per leaf.</p> |tables= |references={{Treatment/Reference |id=fross2006a |text=Fross, D. and D. H. Wilken. 2006. Ceanothus. Portland. }}{{Treatment/Reference |id=nobs1963a |text=Nobs, M. A. 1963. Experimental studies on species relationships in Ceanothus. Publ. Carnegie Inst. Wash. 623. }}{{Treatment/Reference |id=van1942a |text=Van Rensselaer, M. and H. McMinn. 1942. Ceanothus. Santa Barbara. }} }}<!-- --><div class="treatment-key"> ==Key== <div class="treatment-key-group"> {| class="wikitable fna-keytable" |-id=key-0-1 |1 |Stipules thin, deciduous; leaves alternate, blades usually herbaceous, sometimes leathery, pinnately veined or 3-veined from base; inflorescences usually racemelike to paniclelike, sometimes umbel-like; capsules not horned, sometimes crested. |[[Ceanothus subg. Ceanothus|Ceanothus subg. Ceanothus]] |-id=key-0-1 |1 |Stipules thick, persistent, wartlike; leaves opposite (alternate in C. verrucosus and C. megacarpus), blades leathery, pinnately veined; inflorescences usually umbel-like, rarely racemelike; capsules horned or not, usually not crested (crested in C. divergens and C. gloriosus). |[[Ceanothus subg. Cerastes|Ceanothus subg. Cerastes]] |} </div></div><!-- -->{{#Taxon: name=Ceanothus |author=Clifford L. Schmidt†;Dieter H. Wilken |authority=Linnaeus |rank=genus |parent rank=family |synonyms= |basionyms= |family=Rhamnaceae |distribution=North America;Mexico;Central America (Costa Rica);Central America (Guatemala);Central America (Panama) |reference=fross2006a;nobs1963a;van1942a |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_320.xml |genus=Ceanothus |blade architecture=3-veined;veined |blade coloration=not gland-dotted |bud-scale presence=absent |cyme arrangement=aggregated;aggregated |exocarp texture=leathery |flower reproduction=bisexual |hypanthium shape=shallowly cupulate;hemispheric |hypanthium width=0mm;0.5mm |inflorescence position=axillary;terminal |leaf architecture or arrangement=fascicled |leaf arrangement=opposite;alternate |leaf duration=deciduous;persistent |nectary fusion=free |nectary texture=fleshy |ovary architecture or structure in adjective form=3-locular |pedicel presence=absent |pedicel texture=not fleshy |peduncle texture=not fleshy |petal architecture=hooded |petal atypical quantity=6;8 |petal coloration=pink;usually white;cream blue or purple |petal quantity=6;5 |petal shape=clawed;obovate;spatulate |sepal atypical quantity=6;8 |sepal coloration=pink;usually white;cream blue or purple |sepal orientation=spreading;incurved |sepal quantity=6;5 |sepal shape=keeled;lanceolate;deltate |stamen atypical quantity=6;8 |stamen quantity=6 |style fusion=connate |style quantity=3 |thyrse shape=paniclelike;racemelike |whole_organism architecture=unarmed;armed |whole_organism growth form=shrub |x chromosome quantity=12 }}<!-- -->[[Category:Treatment]][[Category:Rhamnaceae]] Templates used on this page: Template:Rhamnaceae (view source) Template:Treatment/AuthorLink (view source) Template:Treatment/Body (view source) Template:Treatment/Body/Maps (view source) Template:Treatment/ID (view source) Template:Treatment/Publication (view source) Template:Treatment/Reference (view source) Return to Ceanothus.