View source for Acanthospermum

{{Treatment/ID
|accepted_name=Acanthospermum
|accepted_authority=Schrank
|publications={{Treatment/Publication
|title=Pl. Rar. Hort. Monac.
|place=2: plate 53. 1820
|year=1820
}}
|basionyms=
|synonyms=
|hierarchy=Asteraceae;Asteraceae tribe Heliantheae;Asteraceae (tribe Heliantheae) subtribe Melampodiinae;Acanthospermum
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Asteraceae]]</div><div class="higher-taxon"><small>tribe</small>[[Asteraceae tribe Heliantheae]]</div><div class="higher-taxon"><small>subtribe</small>[[Asteraceae (tribe Heliantheae) subtribe Melampodiinae]]</div><div class="higher-taxon"><small>genus</small>[[Acanthospermum]]</div></div>
|etymology=Greek acantha, prickle, and sperma, seed, alluding to prickly “fruits”
|volume=Volume 21
|mention_page=page 33
|treatment_page=page 36
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Annuals </b>(sometimes persisting), 10–60(–120) cm. <b>Stems</b> erect to ± prostrate (repeatedly “forked”). <b>Leaves</b> cauline; opposite; petiolate or ± sessile; blades mostly elliptic to deltate, rhombic, or ovate, sometimes lyrate, ultimate margins entire or toothed, faces usually pilosulous to sericeous or scabrellous, sometimes glabrate or glabrescent, usually gland-dotted. <b>Heads</b> radiate, 1(–3) in “forks” of branches (terminal, appearing axillary by sympodial growth). <b>Involucres</b> ± hemispheric, 3–5 mm diam. (becoming ± rotate in fruit). <b>Phyllaries</b> persistent (outer) or falling, 10–13 in 2 series (outer 4–6 herbaceous, inner 5–8 each investing a ray ovary, enlarging in fruit to form a perigynium, shed with enclosed cypsela). <b>Receptacles</b> convex, paleate (paleae cuneate to spatulate, ± conduplicate or flattish, membranous). <b>Ray</b> florets 5–8, pistillate, fertile; corollas yellowish (tubes shorter than to equaling laminae, laminae ovate to elliptic or linear). <b>Disc</b> florets 3–8(–12+), functionally staminate; corollas yellowish, tubes shorter than funnelform or campanulate throats, lobes 5, deltate. <b>Cypselae</b> each enclosed within and shed with an often hardened, ± prickly perigynium (the ultimate “fruits” plumply ellipsoid to fusiform, or ± compressed); pappi 0 or rudimentary. <b>x</b> = 11.</span><!--

-->{{Treatment/Body
|distribution=mostly tropical to warm-temperate New World;also introduced in Old World.
|discussion=<p>Species 6 (3 in the flora).</p>
|tables=
|references={{Treatment/Reference
|id=blake1921a
|text=Blake, S. F. 1921. Revision of the genus Acanthospermum. Contr. U.S. Natl. Herb. 20: 383–392.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Fruits 7–9+ mm, 5–7-ribbed, terminal spines 0
|[[Acanthospermum australe|Acanthospermum australe]]
|-id=key-0-1
|1
|Fruits 2–6 mm, 3-ribbed or not notably ribbed, terminal spines 2
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Leaf blades rhombic-ovate to obovate, (20–)40–120(–150+) mm; fruits not notably ribbed, prickles ± scattered
|[[Acanthospermum hispidum|Acanthospermum hispidum]]
|-id=key-0-2
|2
|Leaf blades ovate to lyrate, 10–30(–45) mm; fruits usually 3-ribbed, prickles mostly along 2 ribs and around apices
|[[Acanthospermum humile|Acanthospermum humile]]
|}
</div></div><!--

-->{{#Taxon:
name=Acanthospermum
|author=John L. Strother
|authority=Schrank
|rank=genus
|parent rank=subtribe
|synonyms=
|basionyms=
|family=Asteraceae
|illustrator=Barbara Alongi
|distribution=mostly tropical to warm-temperate New World;also introduced in Old World.
|introduced=true
|reference=blake1921a
|publication title=Pl. Rar. Hort. Monac.
|publication year=1820
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/9216fc802291cd3df363fd52122300479582ede7/coarse_grained_fna_xml/V19-20-21/V21_70.xml
|tribe=Asteraceae tribe Heliantheae
|subtribe=Asteraceae (tribe Heliantheae) subtribe Melampodiinae
|genus=Acanthospermum
}}<!--

-->[[Category:Treatment]][[Category:Asteraceae (tribe Heliantheae) subtribe Melampodiinae]]