View source for Cerastium

{{Treatment/ID
|accepted_name=Cerastium
|accepted_authority=Linnaeus
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=1: 437. 1753
|year=1753
}}, {{Treatment/Publication
|title=Gen. Pl. ed.
|place=5. 199. 1754
|year=1754
}}
|common_names=Mouse-ear chickweed;céraiste
|basionyms=
|synonyms=
|hierarchy=Caryophyllaceae;Caryophyllaceae subfam. Alsinoideae;Cerastium
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Caryophyllaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Caryophyllaceae subfam. Alsinoideae]]</div><div class="higher-taxon"><small>genus</small>[[Cerastium]]</div></div>
|etymology=Greek, ceras, horn, alluding to shape of capsule
|volume=Volume 5
|mention_page=page 6, 7, 8, 50
|treatment_page=page 74
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole_organism duration;whole_organism duration;whole_organism duration;whole_organism duration;whole_organism duration;whole_organism growth form"><b>Herbs,</b> annual, winter-annual, or perennial.</span> <span class="statement" id="st-d0_s1" data-properties="taproot size;taproot duration;taproot architecture;taproot architecture"><b>Taproots </b>slender, perennial taxa often rhizomatous, rooting at nodes.</span> <span class="statement" id="st-d0_s2" data-properties="stem orientation;stem architecture;stem architecture;stem shape"><b>Stems </b>ascending to erect or decumbent, simple or branched, terete.</span> <span class="statement" id="st-d0_s3" data-properties="leaf fusion;leaf architecture;leaf architecture"><b>Leaves </b>basally connate, petiolate (basal in some species) or sessile (cauline);</span> <span class="statement" id="st-d0_s4" data-properties="blade architecture;blade arrangement or course or shape;blade arrangement or course or shape;blade texture;apex shape">blade 1–5-veined, linear or elliptic to broadly ovate, not succulent (except in C. bialynickii, C. regelii, and C. viride), apex acute to obtuse.</span> <span class="statement" id="st-d0_s5" data-properties="inflorescence position or structure subtype;inflorescence architecture;cyme architecture or arrangement;flower architecture or arrangement or growth form;flower position"><b>Inflorescences </b>terminal, open or congested cymes, or flowers solitary, axillary (racemosely arranged in C. axillare);</span> <span class="statement" id="st-d0_s6" data-properties="bract arrangement;bract architecture;bract size;bract growth form or texture;bract growth form or texture;margin texture">bracts paired, foliaceous or reduced, herbaceous or often with scarious margins.</span> <span class="statement" id="st-d0_s7" data-properties="pedicel orientation;pedicel orientation;pedicel shape;flower architecture"><b>Pedicels </b>erect, sometimes reflexed or hooked at apex in fruit, or flowers sometimes subsessile (C. regelii).</span> <span class="statement" id="st-d0_s8" data-properties="flower reproduction;flower reproduction;flower architecture"><b>Flowers </b>bisexual, occasionally unisexual and pistillate;</span> <span class="statement" id="st-d0_s9" data-properties="perianth position;perianth position;androecium position;androecium position">perianth and androecium hypogynous or weakly perigynous;</span> <span class="statement" id="st-d0_s10" data-properties="">hypanthium minimal;</span> <span class="statement" id="st-d0_s11" data-properties="sepal atypical quantity;sepal quantity;sepal fusion;sepal coloration;sepal shape;sepal some measurement;sepal growth form or texture;margin coloration;margin texture;apex shape;apex shape;apex shape;apex shape;apex shape;apex architecture">sepals (4–) 5, distinct, green (red-tipped in C. glomeratum and C. pumilum, often violet-tipped in C. alpinum, purple in C. bialynickii, turning pale orangebrown in fruit in C. texanum), elliptic to ovate, 3–12 mm, herbaceous, margins translucent to purplish, scarious, apex acute, acuminate, or obtuse, not hooded;</span> <span class="statement" id="st-d0_s12" data-properties="petal atypical quantity;petal quantity;petal presence;petal coloration;petal shape;blade apex shape;blade apex length;blade apex shape;blade apex shape;blade apex shape;blade apex shape">petals (4–) 5 or sometimes absent, white (purple-tinged in C. pumilum and C. regelii), clawed, blade apex 2-fid 1/5–1/2 of length, notched, or emarginate;</span> <span class="statement" id="st-d0_s13" data-properties="filament arrangement;sepal arrangement">nectaries at base of filaments opposite sepals;</span> <span class="statement" id="st-d0_s14" data-properties="stamen quantity;stamen quantity;stamen quantity;stamen quantity">stamens usually 10, sometimes 5 or 8, occasionally 4;</span> <span class="statement" id="st-d0_s15" data-properties="ovary filament fusion">filaments distinct, inserted at base of ovary;</span> <span class="statement" id="st-d0_s16" data-properties="staminode presence;staminode quantity;staminode arrangement or course or shape">staminodes absent or 1–4 (via anther abortion), linear;</span> <span class="statement" id="st-d0_s17" data-properties="style atypical quantity;style atypical quantity;style quantity;style shape;style some measurement;style pubescence">styles (3–) 5 (–6), clavate to filiform, 0.5–2 mm, glabrous proximally;</span> <span class="statement" id="st-d0_s18" data-properties="stigma atypical quantity;stigma atypical quantity;stigma quantity;stigma position;stigma arrangement or course or shape;stigma relief;stigma quantity">stigmas (3–) 5 (–6), subterminal to linear along adaxial surface of styles, roughened to papillate (30×).</span> <span class="statement" id="st-d0_s19" data-properties="capsule shape;capsule shape;capsule course;capsule quantity;capsule quantity;capsule shape;capsule shape;capsule length or size"><b>Capsules </b>oblong or cylindric, usually ± curved, opening by 10, or occasionally 6 or 8, erect or spreading, convolute or revolute teeth, longer than sepals;</span> <span class="statement" id="st-d0_s20" data-properties="carpophore presence">carpophore absent.</span> <span class="statement" id="st-d0_s21" data-properties="seed quantity;seed coloration;seed shape;seed shape;seed relief;marginal wing presence"><b>Seeds </b>15–150+, orange to brown, angular-obovate, often with abaxial groove, laterally compressed, papillate-tuberculate, marginal wing absent, appendage absent.</span> <span class="statement" id="st-d0_s22" data-properties="appendage presence;x chromosome quantity;x chromosome quantity;x chromosome quantity;x chromosome quantity;x chromosome quantity;x chromosome quantity">x = [9?, 13, 15] 17, 18, 19.</span><!--

-->{{Treatment/Body
|distribution=Worldwide;but mainly north-temperate region
|discussion=<p>Species ca. 100 (27 in the flora).</p><!--
--><p>Two names that appear in many North American treatments, Cerastium viscosum Linnaeus and C. vulgatum Linnaeus, have been proposed for rejection (N. J. Turland and M. Wyse Jackson 1997) because they have been a long-standing source of confusion. American authors have frequently applied C. viscosum to C. glomeratum Thuillier but most of the possible lectotypes are referable to C. fontanum. Similarly C. vulgatum has been used for C. fontanum Baumgarten. However the possible lectotypes of C. vulgatum are mixed and most are referable to C. arvense, C. fontanum, and C. glomeratum.</p><!--
--><p>I have not attempted to present an infrageneric classification for Cerastium. Several species groupings can be recognized based on capsule structure. Examples include species with the capsule teeth revolute (coiled outwards like a watch spring), e.g., C. maximum and C. texanum, whereas in most of our species the teeth are erect with their margins outwardly rolled (convolute). Also C. cerastoides is anomalous in having three styles, a straight ovoid-conic capsule, and deeply bilobed petals—characters that have led some authors to place it in the genus Stellaria. Accepting the most recent infrageneric classification (B. K. Schischkin 1936), even with subsequent modifications, does not appear to be warranted. Additional study is needed to determine relevant species relationships within the genus.</p><!--
--><p>While the base chromosome number for Cerastium is often cited as x = 9, only a single count of 2n = 18 is known; see C. Favarger and M. Krähenbühl (1996) for a discussion of the diverse cytological conditions found in Cerastium.</p><!--
--><p>Excluded species:</p><!--
--><p>Cerastium clawsonii Correll, described from Texas, is a synonym of Linum hudsonioides Planchet (R. L. Hartman 1979).</p>
|tables=
|references={{Treatment/Reference
|id=bocher1977a
|text=Böcher, T. W. 1977. Cerastium alpinum and C. arcticum, a mature polyploid complex. Bot. Not. 130: 303–309.
}}{{Treatment/Reference
|id=brysting2000a
|text=Brysting, A. K. and R. Elven. 2000. The Cerastium alpinum–C. arcticum complex (Caryophyllaceae): Numerical analyses of morphological variation and a taxonomic revision of C. arcticum Lange s.l. Taxon 49: 189–216.
}}{{Treatment/Reference
|id=good1984a
|text=Good, D. A. 1984. Revision of the Mexican and Central American species of Cerastium. Rhodora 86: 339–379.
}}{{Treatment/Reference
|id=hulten1956a
|text=Hultén, E. 1956. The Cerastium alpinum complex. A case of world-wide introgressive hybridization. Svensk Bot. Tidsk. 50: 411–495.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Capsules straight, teeth becoming outwardly coiled
|[[#key-0-2| > 2]]
|-id=key-0-1
|1
|Capsules usually curved (rarely straight), teeth erect or sometimes spreading, never coiled, margins convolute
|[[#key-0-3| > 3]]
|-id=key-0-2
|2
|Petals less than 10 mm
|[[Cerastium texanum|Cerastium texanum]]
|-id=key-0-2
|2
|Petals (15-)18-25 mm
|[[Cerastium maximum|Cerastium maximum]]
|-id=key-0-3
|3
|Plants annual, with all shoots producing flowers
|[[#key-0-4| > 4]]
|-id=key-0-3
|3
|Plants perennial, often with nonflowering shoots
|[[#key-0-15| > 15]]
|-id=key-0-4
|4
|Styles 3-4(-5); capsules with 6, 8 (10) teeth
|[[#key-0-5| > 5]]
|-id=key-0-4
|4
|Styles 5; capsules with 10 teeth
|[[#key-0-6| > 6]]
|-id=key-0-5
|5
|Styles 4(-5); stamens 4(-5); capsules 1-1.5 times as long as sepals; cauline leaves ovate to oblong-ovate
|[[Cerastium diffusum|Cerastium diffusum]]
|-id=key-0-5
|5
|Styles 3(-4); stamens 10; capsules ca. 2 times as long as sepals; cauline leaves linear to linear-lanceolate
|[[Cerastium dubium|Cerastium dubium]]
|-id=key-0-6
|6
|Bracts, at least distalmost, with scarious margins
|[[#key-0-7| > 7]]
|-id=key-0-6
|6
|Bracts all completely herbaceous
|[[#key-0-9| > 9]]
|-id=key-0-7
|7
|Stamens 10
|[[Cerastium fontanum|Cerastium fontanum]]
|-id=key-0-7
|7
|Stamens 5
|[[#key-0-8| > 8]]
|-id=key-0-8
|8
|Sepals and distal bracts with broad, scarious margins; petal veins not branched
|[[Cerastium semidecandrum|Cerastium semidecandrum]]
|-id=key-0-8
|8
|Sepals and distal bracts with very narrow, scarious margins; petal veins branched
|[[Cerastium pumilum|Cerastium pumilum]]
|-id=key-0-9
|9
|Sepals with long hairs exceeding sepal tips
|[[#key-0-10| > 10]]
|-id=key-0-9
|9
|Sepals with hairs shorter than sepal tips
|[[#key-0-11| > 11]]
|-id=key-0-10
|10
|Pedicels shorter than capsules; cauline leaf blades broadly ovate or elliptic-ovate
|[[Cerastium glomeratum|Cerastium glomeratum]]
|-id=key-0-10
|10
|Pedicels longer than capsules; cauline leaf blades lanceolate or elliptic
|[[Cerastium brachypetalum|Cerastium brachypetalum]]
|-id=key-0-11
|11
|Flowers racemosely arranged singly in axils of foliaceous bracts along length of stem
|[[Cerastium axillare|Cerastium axillare]]
|-id=key-0-11
|11
|Flowers in terminal dichotomous cymes or clusters
|[[#key-0-12| > 12]]
|-id=key-0-12
|12
|Capsules narrowly conic, straight; stamens 5; pedicels shorter than sepals
|[[Cerastium dichotomum|Cerastium dichotomum]]
|-id=key-0-12
|12
|Capsules cylindric, curved; stamens 10; pedicels shorter than, equaling, or usually longer than sepals
|[[#key-0-13| > 13]]
|-id=key-0-13
|13
|Pedicels equaling or shorter than capsules, often becoming deflexed proximally
|[[Cerastium brachypodum|Cerastium brachypodum]]
|-id=key-0-13
|13
|Pedicels longer than capsules, sharply deflexed distally
|[[#key-0-14| > 14]]
|-id=key-0-14
|14
|Sepals ovate-lanceolate, apex broadly acute to obtuse, inner with broad, scarious margins (ca. as wide as herbaceous center); mid-stem leaf blades lanceolate to narrowly elliptic, 10-60 × 3-15 mm; capsules (9-)10-12(-13) mm
|[[Cerastium nutans|Cerastium nutans]]
|-id=key-0-14
|14
|Sepals narrowly lanceolate, apex sharply acute to acuminate, inner with narrow, scarious margins (narrower than herbaceous center); mid-stem leaf blades linear-lanceolate, 20-70 × 1.5-6 mm; capsules (5-)7-10(-11) mm
|[[Cerastium fastigiatum|Cerastium fastigiatum]]
|-id=key-0-15
|15
|Styles 3 (rarely to 6); capsules straight, ovoid-conic, oblong after dehiscence, teeth 6 (rarely to 12)
|[[Cerastium cerastoides|Cerastium cerastoides]]
|-id=key-0-15
|15
|Styles 5; capsules usually curved, rarely straight, cylindric (rarely broadly conic), teeth 10
|[[#key-0-16| > 16]]
|-id=key-0-16
|16
|Small tufts of leaves in axils of mid and proximal stem leaves
|[[#key-0-17| > 17]]
|-id=key-0-16
|16
|Small tufts of leaves usually absent from axils of mid and proximal stem leaves (normal leafy shoots may be present)
|[[#key-0-20| > 20]]
|-id=key-0-17
|17
|Petals 7.5-9 mm; sepals 3.5-6(-7) mm; flowering stems 5-20(-30) cm; anthers 0.8-0.9 mm
|[[Cerastium arvense|Cerastium arvense]]
|-id=key-0-17
|17
|Petals 10-15 mm; sepals 5-9 mm; flowering stems 15-45 cm; anthers 0.9-1.2 mm
|[[#key-0-18| > 18]]
|-id=key-0-18
|18
|Plants taprooted, tufted, with or without short, nonflowering, leafy shoots; pubescence on proximal stem spreading; e North America
|[[Cerastium velutinum|Cerastium velutinum]]
|-id=key-0-18
|18
|Plants with long-creeping rhizomes; pubescence on proximal stems deflexed
|[[#key-0-19| > 19]]
|-id=key-0-19
|19
|Capsules 2.5-4 mm wide; sepals 5-7 mm; seeds 0.6-1.2 mm; introduced lawn weed
|[[Cerastium arvense|Cerastium arvense]]
|-id=key-0-19
|19
|Capsules 4-5 mm wide; sepals 6-9 mm; seeds 1-1.5 mm; Pacific coastal region
|[[Cerastium viride|Cerastium viride]]
|-id=key-0-20
|20
|Leaf surfaces obscured by dense white tomentum
|[[Cerastium tomentosum|Cerastium tomentosum]]
|-id=key-0-20
|20
|Leaf surfaces clearly visible through pubescence or leaf blades glabrous
|[[#key-0-21| > 21]]
|-id=key-0-21
|21
|Long flexuous hairs present on stems and/or leaf blades
|[[Cerastium alpinum|Cerastium alpinum]]
|-id=key-0-21
|21
|Long flexuous hairs absent, pubescence of straight or deflexed, short or long hairs
|[[#key-0-22| > 22]]
|-id=key-0-22
|22
|Gland-tipped hairs absent, pubescence eglandular throughout
|[[#key-0-23| > 23]]
|-id=key-0-22
|22
|Gland-tipped hairs present at least in inflorescences
|[[#key-0-24| > 24]]
|-id=key-0-23
|23
|Inflorescences with 3+ flowers; stems 10-45 cm; leaves not marcescent; ubiquitous weed
|[[Cerastium fontanum|Cerastium fontanum]]
|-id=key-0-23
|23
|Inflorescences with 1(-3) flowers; stems 3-7 cm; proximal leaves marcescent; w arctic native
|[[Cerastium aleuticum|Cerastium aleuticum]]
|-id=key-0-24
|24
|Testa of seeds inflated, loose (rubs off when rolled between finger and thumb); Newfoundland
|[[Cerastium terrae-novae|Cerastium terrae-novae]]
|-id=key-0-24
|24
|Testa of seeds not inflated, closely and firmly enclosing seed; North America, rarely in Newfoundland
|[[#key-0-25| > 25]]
|-id=key-0-25
|25
|Plants pulvinate; stems 1-10 cm
|[[#key-0-26| > 26]]
|-id=key-0-25
|25
|Plants rhizomatous, mat-forming or tufted, not pulvinate; stems 5-50 cm
|[[#key-0-27| > 27]]
|-id=key-0-26
|26
|Plants rarely flowering; leaf blades subglabrous or with few colorless cilia
|[[Cerastium regelii|Cerastium regelii]]
|-id=key-0-26
|26
|Plants normally flowering; leaf blades densely hispid with long, fuscous hairs
|[[Cerastium bialynickii|Cerastium bialynickii]]
|-id=key-0-27
|27
|Petals ± equaling sepals
|[[#key-0-28| > 28]]
|-id=key-0-27
|27
|Petals 1.5-2 times as long as sepals
|[[#key-0-29| > 29]]
|-id=key-0-28
|28
|Proximal bracts foliaceous
|[[Cerastium beeringianum|Cerastium beeringianum]]
|-id=key-0-28
|28
|Proximal bracts herbaceous, lanceolate, reduced
|[[Cerastium fontanum|Cerastium fontanum]]
|-id=key-0-29
|29
|Sepals 6-11 mm, narrowly lanceolate-triangular, apex acute or acuminate, scarious margins narrow
|[[#key-0-30| > 30]]
|-id=key-0-29
|29
|Sepals 3-7 mm, lanceolate to broadly elliptic, apex obtuse to ± acute, scarious margins broad
|[[#key-0-31| > 31]]
|-id=key-0-30
|30
|Apices of mid and distal stem leaf blades acute; pubescence on stem and leaf blades long, dense, yellowish; inflorescences 2-10-flowered; w arctic
|[[Cerastium fischerianum|Cerastium fischerianum]]
|-id=key-0-30
|30
|Apices of mid and distal stem leaf blades usually round and obtuse; pubescence colorless to somewhat fuscous; inflorescences 1-3-flowered; e arctic
|[[Cerastium arcticum|Cerastium arcticum]]
|-id=key-0-31
|31
|Sepals with ± acute apex; leaf blades not succulent, pubescent, those on flowering shoots with ± acute apex; petals usually equaling, rarely to 2 times as long as sepals; plants taprooted, forming clumps, rarely rhizomatous
|[[Cerastium beeringianum|Cerastium beeringianum]]
|-id=key-0-31
|31
|Sepals with obtuse apex; leaf blades succulent, subglabrous to ciliate with long, colorless hairs, rotund, obovate, broadly elliptic, or broadly lanceolate, apex obtuse; petals 1.5-2 times as long as sepals; plants strongly rhizomatous with nonflowering, creeping shoots 6-30 cm
|[[Cerastium regelii|Cerastium regelii]]
|}
</div></div><!--

-->{{#Taxon:
name=Cerastium
|author=John K. Morton
|authority=Linnaeus
|rank=genus
|parent rank=subfamily
|synonyms=
|basionyms=
|family=Caryophyllaceae
|illustrator=Yevonn Wilson-Ramsey
|illustration copyright=Flora of North America Association
|distribution=Worldwide;but mainly north-temperate region
|reference=bocher1977a;brysting2000a;good1984a;hulten1956a
|publication title=Sp. Pl.;Gen. Pl. ed.
|publication year=1753;1754
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V5/V5_156.xml
|subfamily=Caryophyllaceae subfam. Alsinoideae
|genus=Cerastium
|androecium position=perigynous;hypogynous
|apex architecture=not hooded
|apex shape=obtuse;acuminate;obtuse;acuminate;acute;acute;obtuse
|appendage presence=absent
|blade apex length=1/5;1/2
|blade apex shape=emarginate;notched;emarginate;notched;2-fid
|blade architecture=1-5-veined
|blade arrangement or course or shape=elliptic to broadly ovate;linear
|blade texture=not succulent
|bract architecture=foliaceous
|bract arrangement=paired
|bract growth form or texture=often;herbaceous
|bract size=reduced
|capsule course=curved
|capsule length or size=longer
|capsule quantity=8;6
|capsule shape=revolute;convolute;cylindric;oblong
|carpophore presence=absent
|cyme architecture or arrangement=congested
|filament arrangement=opposite
|flower architecture=pistillate;subsessile
|flower architecture or arrangement or growth form=solitary
|flower position=axillary
|flower reproduction=unisexual;bisexual
|inflorescence architecture=open
|inflorescence position or structure subtype=terminal
|leaf architecture=sessile;petiolate
|leaf fusion=connate
|margin coloration=translucent;purplish
|margin texture=scarious;scarious
|marginal wing presence=absent
|ovary filament fusion=distinct
|pedicel orientation=reflexed;erect
|pedicel shape=hooked
|perianth position=perigynous;hypogynous
|petal atypical quantity=4;5
|petal coloration=white
|petal presence=absent
|petal quantity=5
|petal shape=clawed
|seed coloration=orange;brown
|seed quantity=15;150
|seed relief=papillate-tuberculate
|seed shape=compressed;angular-obovate
|sepal arrangement=opposite
|sepal atypical quantity=4;5
|sepal coloration=green
|sepal fusion=distinct
|sepal growth form or texture=herbaceous
|sepal quantity=5
|sepal shape=elliptic;ovate
|sepal some measurement=3mm;12mm
|stamen quantity=4;8;5;10
|staminode arrangement or course or shape=linear
|staminode presence=absent
|staminode quantity=1;4
|stem architecture=branched;simple
|stem orientation=ascending;erect or decumbent
|stem shape=terete
|stigma arrangement or course or shape=linear
|stigma atypical quantity=5;6
|stigma position=subterminal
|stigma quantity=[30;5
|stigma relief=roughened;papillate
|style atypical quantity=5;6
|style pubescence=glabrous
|style quantity=5
|style shape=clavate;filiform
|style some measurement=0.5mm;2mm
|taproot architecture=rooting;rhizomatous
|taproot duration=perennial
|taproot size=slender
|whole_organism duration=perennial;winter-annual;perennial;winter-annual;annual
|whole_organism growth form=herb
|x chromosome quantity=19;18;17;15];13;[9
}}<!--

-->[[Category:Treatment]][[Category:Caryophyllaceae subfam. Alsinoideae]]