{{Short description|Family of plants}} {{Automatic taxobox |image = HELIOTROPIUM_EUROPAEUM_-_AGUDA_-_IB-323_(Herba_berruguera).JPG |image_caption = ''Heliotropium europaeum'' |taxon = Heliotropiaceae |authority = Schrad. |subdivision_ranks = Genera |subdivision = See text. }} '''Heliotropiaceae''' are a cosmopolitan family of flowering plants with approximately 450 species worldwide, though it is concentrated especially in the tropics and subtropics.<ref name=":0">{{Cite journal|last1=Luebert|first1=Federico|last2=Cecchi|first2=Lorenzo|last3=Frohlich|first3=Michael W.|last4=Gottschling|first4=Marc|last5=Guilliams|first5=C. Matt|last6=Hasenstab-Lehman|first6=Kristen E.|last7=Hilger|first7=Hartmut H.|last8=Miller|first8=James S.|last9=Mittelbach|first9=Moritz|last10=Nazaire|first10=Mare|last11=Nepi|first11=Massimo|date=2016-06-24|title=Familial classification of the Boraginales|url=http://doi.wiley.com/10.12705/653.5|journal=Taxon|language=en|volume=65|issue=3|pages=502–522|doi=10.12705/653.5|bibcode=2016Taxon..65..502L |hdl=11365/993946 |issn=0040-0262|hdl-access=free}}</ref>
== Description == In broad terms, members of the Heliotropiaceae are quite diverse in that they can be small trees, lianas, shrubs, sub-shrubs, or even perennial or annual herbs. However they all have 5-merous, tetracyclic flowers and actinomorphic corollas. These plants are also characterized by their terminal styles and highly modified stigmatic heads (basal stigma, infertile apex) as well as by their fruits (one or two-seeded mericarpids or drupes).<ref name=":1" /> Their conical stigmatic heads are unique and are thus a recognizable synapomorphy for this family. Heliotropiaceae mostly have distinctly scorpioid cymose inflorescences.<ref name=":0" />
==Taxonomy== In a 2014 phylogenetic study, ''Ixorhea'' was sister to ''Euploca'' and ''Myriopus''.<ref>{{Cite journal|last1=Weigend|first1=Maximilian|last2=Luebert|first2=Federico|last3=Gottschling|first3=Marc|last4=Couvreur|first4=Thomas L.P.|last5=Hilger|first5=Hartmut H.|last6=Miller|first6=James S.|date=October 2014|title=From capsules to nutlets-phylogenetic relationships in the Boraginales|journal=Cladistics|language=en|volume=30|issue=5|pages=508–518|doi=10.1111/cla.12061|pmid=34794245|s2cid=11954615|doi-access=free}}</ref> Together they form a clade sister to ''Heliotropium'', which comprises four major clades: ''Heliotropium'' sect. ''Heliothamnus'' I.M.Johnst., Old World ''Heliotropium'', ''Heliotropium'' sect. ''Cochranea'' (Miers) Post & Kuntze, and the ''Tournefortia''-clade, the latter comprising ''Tournefortia'' sect. ''Tournefortia'' and all remaining New World species of ''Heliotropium''.<ref>{{Cite journal|last1=Hilger|first1=Hartmut H.|last2=Diane|first2=Nadja|date=2003-12-17|title=A systematic analysis of Heliotropiaceae (Boraginales) based on trnL and ITS1 sequence data|url=http://www.schweizerbart.de/papers/pde/detail/125/52666/A_systematic_analysis_of_Heliotropiaceae_Boraginal?af=crossref|journal=Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie|language=en|volume=125|issue=1|pages=19–51|doi=10.1127/0006-8152/2003/0125-0019|issn=0006-8152|url-access=subscription}}</ref><ref>{{Cite journal|last1=Luebert|first1=Federico|last2=Brokamp|first2=Grischa|last3=Wen|first3=Jun|last4=Weigend|first4=Maximilian|last5=Hilger|first5=Hartmut H.|date=June 2011|title=Phylogenetic relationships and morphological diversity in Neotropical Heliotropium (Heliotropiaceae)|url=https://onlinelibrary.wiley.com/doi/10.1002/tax.603004|journal=Taxon|language=en|volume=60|issue=3|pages=663–680|doi=10.1002/tax.603004|bibcode=2011Taxon..60..663L |url-access=subscription|hdl=10533/143421|hdl-access=free}}</ref>
=== History === Prior to a 2016 revision, Heliotropiaceae were considered a subfamily of the Boraginaceae: Heliotropioideae.<ref name=":0" /> Even before that, however, there was already some indication in the field that Heliotropiaceae deserved to be recognized as an independent family. Anatomically, the presence of anatropous ovules in Heliotropiaceae as well as the presence of long suspensors and endosperm haustoria in Boraginaceae drove the earliest divide between the two families in the literature. Later, molecular data collected from a variety of families in the Boraginales collectively indicated that the Hydrophyllaceae were sister to the Heliotropiaceae, something that rendered the Boraginaceae paraphyletic.<ref name=":1">{{Cite journal|last1=Diane|first1=N.|last2=Forther|first2=H.|last3=Hilger|first3=H. H.|date=2002-02-01|title=A systematic analysis of Heliotropium, Tournefortia, and allied taxa of the Heliotropiaceae (Boraginales) based on ITS1 sequences and morphological data|url=http://doi.wiley.com/10.3732/ajb.89.2.287|journal=American Journal of Botany|language=en|volume=89|issue=2|pages=287–295|doi=10.3732/ajb.89.2.287|pmid=21669738|bibcode=2002AmJB...89..287D |issn=0002-9122|url-access=subscription}}</ref>
===Genera=== {{As of|2025|December}}, World Flora Online accepted three genera:<ref name=WFO_4100001212>{{Cite WFO |title=Heliotropiaceae Schrad. |id=4100001212 |access-date=2025-12-16}}</ref> * ''Euploca'' <small>Nutt.</small> * ''Heliotropium'' <small>L.</small> * ''Ixorhea'' <small>Fenzl</small> It places ''Myriopus'', which has been included in the family, in Boraginaceae.<ref name=WFO_4000025147>{{Cite WFO |title=''Myriopus'' Small |id=4000025147 |access-date=2025-12-16}}</ref>
==References== {{Reflist}}
{{Taxonbar|from=Q19680787}}
Category:Heliotropiaceae Category:Asterid families