View source for Acaena

{{Treatment/ID
|accepted_name=Acaena
|accepted_authority=Mutis ex Linnaeus
|publications={{Treatment/Publication
|title=Mant. Pl.,
|place=145, 200. 1771
|year=1771
}}
|basionyms=
|synonyms=
|hierarchy=Rosaceae;Rosaceae subfam. Rosoideae;Rosaceae tribe Agrimonieae;Acaena
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Rosaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Rosaceae subfam. Rosoideae]]</div><div class="higher-taxon"><small>tribe</small>[[Rosaceae tribe Agrimonieae]]</div><div class="higher-taxon"><small>genus</small>[[Acaena]]</div></div>
|etymology=Greek akaina, thorn, alluding to barbed spines arising from wall of hypanthium
|volume=Volume 9
|mention_page=page 19, 312
|treatment_page=page 323
}}<!--

--><span class="statement" id="st-d0_s0" data-properties=""><b>Herbs,</b> perennial, 1–15 dm diam.;</span> <span class="statement" id="st-d0_s1" data-properties="whole_organism duration;whole_organism diameter;whole_organism architecture;whole_organism growth form">from branched, woody caudex or stoloniferous.</span> <span class="statement" id="st-d0_s2" data-properties="stem quantity;stem growth form or orientation;stem architecture;stem orientation;stem texture;stem pubescence;stem pubescence;leaf-base life cycle"><b>Stems </b>1–20, creeping and rooting or suberect, basally woody, clad in old leaf-bases, glabrous or sparsely pilose.</span> <span class="statement" id="st-d0_s3" data-properties="leaf duration"><b>Leaves </b>persistent, basal and/or cauline;</span> <span class="statement" id="st-d0_s4" data-properties="stipule presence;stipule duration;stipule fusion;portion fusion;portion shape;portion shape;portion shape;margin architecture or shape">stipules absent or persistent, adnate to petiole, free portion ovate to obovate, deeply 2–5-fid, or linear, margins entire;</span> <span class="statement" id="st-d0_s5" data-properties="petiole presence">petiole present;</span> <span class="statement" id="st-d0_s6" data-properties="blade shape;blade atypical some measurement;blade atypical some measurement;blade some measurement;blade growth form or texture;leaflet quantity;leaflet arrangement;leaflet shape;leaflet shape;leaflet shape;leaflet shape;leaflet shape;margin shape;margin shape;margin shape;margin architecture or shape;margin architecture or shape;margin architecture or shape;surface pubescence;surface pubescence">blade spatulate, [1–] 2–15 [–18] cm, herbaceous, leaflets 4–10 per side, opposite, ovate, oblong, or elliptic, margins flat or revolute, incised or pinnatisect, dentate or entire, surfaces hairy or glabrous.</span> <span class="statement" id="st-d0_s7" data-properties="inflorescence position;inflorescence position;inflorescence architecture;head shape"><b>Inflorescences </b>terminal or axillary, [4–] 15–100-flowered, spikes or globose heads;</span> <span class="statement" id="st-d0_s8" data-properties="peduncle presence;peduncle presence">peduncles present or absent;</span> <span class="statement" id="st-d0_s9" data-properties="bract presence">bracts absent;</span> <span class="statement" id="st-d0_s10" data-properties="bracteole presence">bracteoles present.</span> <span class="statement" id="st-d0_s11" data-properties="pedicel presence"><b>Pedicels </b>present.</span> <span class="statement" id="st-d0_s12" data-properties="flower diameter"><b>Flowers </b>3.5–6 mm diam.;</span> <span class="statement" id="st-d0_s13" data-properties="hypanthium shape;hypanthium shape;hypanthium shape;hypanthium shape;hypanthium shape;hypanthium diameter;hypanthium architecture or shape;hypanthium pubescence;hypanthium pubescence">hypanthium obtriangular, ovoid, or obconic, 3.5–6 mm diam., spiny [or winged or neither], tomentose or glabrous;</span> <span class="statement" id="st-d0_s14" data-properties="sepal atypical quantity;sepal quantity;sepal orientation;sepal shape;sepal shape">sepals 4–5 [–6], spreading, elliptic or triangular;</span> <span class="statement" id="st-d0_s15" data-properties="petal presence">petals 0;</span> <span class="statement" id="st-d0_s16" data-properties="stamen atypical quantity;stamen quantity;stamen length or size">stamens 2–4 [–6], longer than sepals;</span> <span class="statement" id="st-d0_s17" data-properties="carpel quantity;style coloration;style coloration;style shape">carpels 1 [or 2], styles white or red, fimbriate.</span> <span class="statement" id="st-d0_s18" data-properties="fruits achene atypical quantity;fruits achene quantity;fruits achene shape"><b>Fruits </b>achenes, 1 [–2], spindle-shaped;</span> <span class="statement" id="st-d0_s19" data-properties="hypanthium duration;hypanthium coloration;hypanthium shape;hypanthium shape;hypanthium shape;hypanthium shape;hypanthium shape;hypanthium shape;hypanthium diameter;hypanthium texture;hypanthium architecture;hypanthium shape;spine quantity;angle quantity;spine atypical quantity;spine quantity;spine pubescence;spine pubescence;spine architecture;spine architecture;hair orientation;barb orientation">hypanthium persistent, enclosing achenes, gray to redbrown, ovoid, oblong, globose, or obconic, 3–6 mm diam., hardened, sometimes winged, distinctly or obscurely angled with a single spine at apex of each of 4 angles, or covered with 10–20 [–50] spines [or without spines], spines usually bearing retrorse hairs or barbs at apices, pubescent or glabrous, eglandular or glandular;</span> <span class="statement" id="st-d0_s20" data-properties="">sepals persistent, spreading.</span> <span class="statement" id="st-d0_s21" data-properties="sepal duration;sepal orientation;x chromosome quantity">x = 21.</span><!--

-->{{Treatment/Body
|distribution=w United States;Mexico;South America (Argentina);South America (Chile);s Africa (Cape Province);Atlantic Islands (Gough Island);Atlantic Islands (South Georgia);Atlantic Islands (Tristan da Cunha);Indian Ocean Islands (Kerguelen);Indian Ocean Islands (Prince Edward Island);Pacific Islands (Hawaii);Pacific Islands (New Guinea);Pacific Islands (New Zealand);Australia; in Europe (England); in Europe (Ireland)
|discussion=<p>Species ca. 45 (3 in the flora).</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Inflorescences interrupted spikes; fruiting hypanthia bearing 10–20 spines 1–3 mm; plants decumbent to suberect; leaflets pinnatisect.
|[[Acaena pinnatifida|Acaena pinnatifida]]
|-id=key-0-1
|1
|Inflorescences globose heads; fruiting hypanthia 4-angled, each angle with a spine at apex (arising distally) 7–15 mm; plants creeping or stoloniferous; leaflets dentate
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Fruiting hypanthia: spines 7–12 mm, without subsidiary spines on angles; stems 1.5–2 mm diam.; leaflet adaxial surfaces bright shining green, smooth, abaxial surfaces glaucescent.
|[[Acaena novae-zelandiae|Acaena novae-zelandiae]]
|-id=key-0-2
|2
|Fruiting hypanthia: spines 9–15 mm, with subsidiary spines on angles; stems 2–3 mm diam.; leaflet adaxial surfaces glossy green, rugulose, abaxial surfaces whitish with uneven wax layer.
|[[Acaena pallida|Acaena pallida]]
|}
</div></div><!--

-->{{#Taxon:
name=Acaena
|author=Bryony Macmillan
|authority=Mutis ex Linnaeus
|rank=genus
|parent rank=tribe
|synonyms=
|basionyms=
|family=Rosaceae
|distribution=w United States;Mexico;South America (Argentina);South America (Chile);s Africa (Cape Province);Atlantic Islands (Gough Island);Atlantic Islands (South Georgia);Atlantic Islands (Tristan da Cunha);Indian Ocean Islands (Kerguelen);Indian Ocean Islands (Prince Edward Island);Pacific Islands (Hawaii);Pacific Islands (New Guinea);Pacific Islands (New Zealand);Australia; in Europe (England); in Europe (Ireland)
|reference=None
|publication title=Mant. Pl.,
|publication year=1771
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V9/V9_528.xml
|subfamily=Rosaceae subfam. Rosoideae
|tribe=Rosaceae tribe Agrimonieae
|genus=Acaena
|angle quantity=4
|barb orientation=retrorse
|blade atypical some measurement=15cm;18cm
|blade growth form or texture=herbaceous
|blade shape=spatulate
|blade some measurement=2cm;15cm
|bract presence=absent
|bracteole presence=absent
|carpel quantity=1
|flower diameter=3.5mm;6mm
|fruits achene atypical quantity=1;2
|fruits achene quantity=1
|fruits achene shape=spindle--shaped
|hair orientation=retrorse
|head shape=globose
|hypanthium architecture=winged
|hypanthium architecture or shape=spiny
|hypanthium coloration=gray;redbrown
|hypanthium diameter=3mm;6mm
|hypanthium duration=persistent
|hypanthium pubescence=glabrous;tomentose
|hypanthium shape=angled;obconic;globose;obconic;globose;oblong;ovoid;obconic;ovoid;obconic;ovoid;obtriangular
|hypanthium texture=hardened
|inflorescence architecture=[4-]15-100-flowered
|inflorescence position=axillary;terminal
|leaf duration=persistent
|leaf-base life cycle=old
|leaflet arrangement=opposite
|leaflet quantity=4;10
|leaflet shape=elliptic;oblong;elliptic;oblong;ovate
|margin architecture or shape=entire;dentate;pinnatisect;entire
|margin shape=incised;revolute;flat
|pedicel presence=absent
|peduncle presence=absent;absent
|petal presence=absent
|petiole presence=absent
|portion fusion=free
|portion shape=ovate;obovate deeply 2-5-fid or linear
|sepal atypical quantity=5;6
|sepal duration=persistent
|sepal orientation=spreading;spreading
|sepal quantity=4;5
|sepal shape=triangular;elliptic
|spine architecture=glandular;eglandular
|spine atypical quantity=20;50
|spine pubescence=glabrous;pubescent
|spine quantity=10;20
|stamen atypical quantity=4;6
|stamen length or size=longer
|stamen quantity=2;4
|stem architecture=rooting
|stem growth form or orientation=creeping
|stem orientation=suberect
|stem pubescence=pilose;glabrous
|stem quantity=1;20
|stem texture=woody
|stipule duration=persistent
|stipule fusion=adnate
|stipule presence=absent
|style coloration=red;white
|style shape=fimbriate
|surface pubescence=glabrous;hairy
|whole_organism architecture=stoloniferous
|whole_organism diameter=1dm;15dm
|whole_organism duration=perennial
|whole_organism growth form=herb
|x chromosome quantity=21
}}<!--

-->[[Category:Treatment]][[Category:Rosaceae tribe Agrimonieae]]