Editing Kelp (section)

== Taxonomy ==
=== Phylogeny ===

Seaweed were generally considered homologues of [[terrestrial plant]]s,<ref>Darwin, C. ''The Voyage of the Beagle''; P. F. Collier & Son Corporation: New York, 1860</ref>  but are only very distantly related to plants, and have evolved plant-like structures through [[convergent evolution]].<ref name="Drobnitch-2015">{{Cite journal |last1=Drobnitch |first1=Sarah Tepler |last2=Jensen |first2=Kaare H. |last3=Prentice |first3=Paige |last4=Pittermann |first4=Jarmila |date=2015-10-07 |title=Convergent evolution of vascular optimization in kelp (Laminariales) |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=282 |issue=1816 |pages=20151667 |doi-access=free |doi=10.1098/rspb.2015.1667 |issn=0962-8452 |pmc=4614777 |pmid=26423844}}</ref> Where plants have leaves, stems, and reproductive organs, kelp have independently evolved blades, stipes, and [[sporangia]]. With [[radiometric dating]] and the measure Ma “unequivocal minimum constraint for total group [[Pinaceae]]” [[vascular plant]]s have been measured as having evolved around 419–454 [[Before Present|Ma]]<ref>{{Cite journal |last1=Clarke |first1=John T. |last2=Warnock |first2=Rachel C. M. |last3=Donoghue |first3=Philip C. J. |date=October 2011 |title=Establishing a time-scale for plant evolution |journal=New Phytologist |language=en |volume=192 |issue=1 |pages=266–301 |doi=10.1111/j.1469-8137.2011.03794.x |pmid=21729086 |doi-access=free |issn=0028-646X}}</ref> while the ancestors of Laminariales are much younger at 189 Ma.<ref>{{Cite journal |last1=Silberfeld |first1=Thomas |last2=Leigh |first2=Jessica W. |last3=Verbruggen |first3=Heroen |last4=Cruaud |first4=Corinne |last5=de Reviers |first5=Bruno |last6=Rousseau |first6=Florence |date=August 2010 |title=A multi-locus time-calibrated phylogeny of the brown algae (Heterokonta, Ochrophyta, Phaeophyceae): Investigating the evolutionary nature of the "brown algal crown radiation" |journal=Molecular Phylogenetics and Evolution |volume=56 |issue=2 |pages=659–674 |doi=10.1016/j.ympev.2010.04.020 |pmid=20412862|bibcode=2010MolPE..56..659S }}</ref> Although these groups are distantly related as well as different in evolutionary age, there are still comparisons that can be made between the structures of terrestrial plants and kelp but in terms of evolutionary history, most of these similarities come from convergent evolution.

Some kelp species including giant kelp, have evolved transport mechanisms for organic as well as [[inorganic compound]]s,<ref>{{Cite journal |last=Manley |first=Steven L. |date=March 1983 |title=Composition of Sieve Tube Sap from Macrocystis Pyrifera (Phaeophyta) With Emphasis on the Inorganic Constituents |journal=Journal of Phycology |language=en |volume=19 |issue=1 |pages=118–121 |doi=10.1111/j.0022-3646.1983.00118.x |bibcode=1983JPcgy..19..118M |s2cid=84778708 |issn=0022-3646}}</ref> similar to mechanisms of transport in [[tree]]s and other [[vascular plant]]s. In kelp this transportation network uses trumpet-shaped sieve elements (SEs). A 2015 study aimed to evaluate the efficiency of [[giant kelp]] (''Macrocystis pyrifera'') transport anatomy looked at 6 different laminariales species to see if they had typical vascular plant allometric relationships (if SEs had a correlation with the size of an organism). Researchers expected to find the kelp’s phloem to work similarly to a plant's [[xylem]] and therefore display similar [[Allometry|allometric]] trends to minimize [[pressure gradient]]. The study found no universal allometric scaling between all tested structures of the laminariales species which implies that the transport network of brown algae is only just beginning to evolve to efficiently fit their current niches.<ref name="Drobnitch-2015" />

Apart from undergoing convergent evolution with plants, species of kelp have undergone convergent evolution within their own phylogeny that has led to [[Phylogenetic niche conservatism|niche conservatism]].<ref name="Starko-2020">{{Cite journal |last1=Starko |first1=Samuel |last2=Demes |first2=Kyle W. |last3=Neufeld |first3=Christopher J. |last4=Martone |first4=Patrick T. |date=October 2020 |editor-last=Carrington |editor-first=Emily |title=Convergent evolution of niche structure in Northeast Pacific kelp forests |journal=Functional Ecology |language=en |volume=34 |issue=10 |pages=2131–2146 |doi=10.1111/1365-2435.13621 |doi-access=free |bibcode=2020FuEco..34.2131S |issn=0269-8463}}</ref> This niche conservatism means that some species of kelp have convergently evolved to share similar niches, as opposed to all species diverging into distinct niches through [[adaptive radiation]]. A 2020 study looked at functional traits (blade mass per area, stiffness, strength, etc.) of 14 species of kelp and found that many of these traits evolved convergently across kelp phylogeny. With different species of kelp filling slightly different environmental niches, specifically along a wave disturbance gradient, many of these convergently evolved traits for structural reinforcement also correlate with distribution along that gradient. The wave disturbance gradient that this study refers to is the environments that this kelp inhabit have a varied level of perturbation from the [[tide]] and waves that pull at the kelp. It can be assumed from these results that niche partitioning along wave disturbance gradients is a key driver of divergence between closely related kelp.<ref name="Starko-2020" />

Due to the often varied and turbulent habitat that kelp populate, [[Phenotypic plasticity|plasticity]] of certain structural traits has been a key for the evolutionary history of the phyla. Plasticity helps with a very important aspect of kelp adaptations to ocean environments, and that is the unusually high levels of morphological [[homoplasy]] between lineages. This in fact has made classifying brown algae difficult.<ref>{{Cite journal |last1=Draisma |first1=Stefano G. A. |last2=Prud'Homme van Reine |first2=Willem F. |last3=Stam |first3=Wytze T. |last4=Olsen |first4=Jeanine L. |date=August 2001 |title=A Reassessment of Phylogenetic Relationships Within the Phaeophyceae Based on Rubisco Large Subunit and Ribosomal DNA Sequences |journal=Journal of Phycology |language=en |volume=37 |issue=4 |pages=586–603 |doi=10.1046/j.1529-8817.2001.037004586.x |bibcode=2001JPcgy..37..586D |s2cid=83876632 |issn=0022-3646}}</ref> Kelp often have similar [[Morphology (biology)|morphological]] features to other species within its own area since the roughness of the wave disturbance regime, but can look fairly different from other members of its own species that are found in different wave disturbance regimes. Plasticity in kelps most often involves blade morphology such as the width, ruffle, and thickness of blades.<ref name="Koehl-2008">{{Cite journal |last1=Koehl |first1=M. A. R. |last2=Silk |first2=W. K. |last3=Liang |first3=H. |last4=Mahadevan |first4=L. |date=December 2008 |title=How kelp produce blade shapes suited to different flow regimes: A new wrinkle |journal=Integrative and Comparative Biology |volume=48 |issue=6 |pages=834–851 |doi=10.1093/icb/icn069 |pmid=21669836 |doi-access=free |issn=1540-7063}}</ref> Just one example is the giant bull kelp ''[[Bull kelp|Nereocystis luetkeana]]'', which have evolved to change blade shape in order to increase drag in water and interception of light when exposed to certain environments. Bull kelp are not unique in this adaptation; many kelp species have evolved a genetic plasticity for blade shapes for different water flow habitats. So individuals of the same species will have differences to other individuals of the same species due to what [[habitat]] they grow in.<ref>Lobban, C. S., Wynne, M. J., & Lobban. (1981). ''The Biology of Seaweeds''. University of California Press.</ref> Many species have different [[Morphology (biology)|morphologies]] for different wave disturbance regimes<ref name="Koehl-2008" /> but giant kelp ''[[Macrocystis|Macrocystis integrifolia]]'' has been found to have plasticity allowing for 4 distinct types of blade morphology depending on habitat.<ref>{{Cite journal |last1=Hurd |first1=C. L. |last2=Harrison |first2=P. J. |last3=Druehl |first3=L. D. |date=August 1996 |title=Effect of seawater velocity on inorganic nitrogen uptake by morphologically distinct forms of Macrocystis integrifolia from wave-sheltered and exposed sites  |journal=Marine Biology |language=en |volume=126 |issue=2 |pages=205–214 |doi=10.1007/BF00347445 |bibcode=1996MarBi.126..205H |s2cid=84195060 |issn=1432-1793}}</ref> Where many species only have two or three different blade shapes for maximizing efficiency in only two or three habitats. These different blade shapes were found to decrease breakage and increase ability to [[Photosynthesis|photosynthesize]]. Blade adaptations like these are how kelp have evolved for efficiency in structure in a turbulent ocean environment, to the point where their stability can shape entire habitats. Apart from these structural adaptations, the evolution of dispersal methods relating to structure have been important for the success of kelp as well.

Kelp have had to adapt [[Biological dispersal|dispersal]] methods that can make successful use of [[ocean current]]s. [[Buoyancy]] of certain kelp structures allows for species to disperse with the flow of water.<ref>{{Cite journal |last1=Garden |first1=Christopher J. |last2=Currie |first2=Kim |last3=Fraser |first3=Ceridwen I. |last4=Waters |first4=Jonathan M. |date=2014-03-31 |title=Rafting dispersal constrained by an oceanographic boundary |journal=Marine Ecology Progress Series |language=en |volume=501 |pages=297–302 |doi-access= |doi=10.3354/meps10675 |bibcode=2014MEPS..501..297G |issn=0171-8630}}</ref> Certain kelp form kelp rafts, which can travel great distances away from the source [[population]] and colonize other areas. The bull kelp genus ''Durvillaea'' includes six species, some that have adapted buoyancy and others that have not. Those that have adapted buoyancy have done so thanks to the evolution of a gas filled structure called the [[pneumatocyst]]s which is an adaptation that allows the kelp to float higher towards the surface to photosynthesize and also aids in dispersal by floating kelp rafts.<ref>{{Cite journal |last1=Fraser |first1=Ceridwen I. |last2=Velásquez |first2=Marcel |last3=Nelson |first3=Wendy A. |last4=Macaya |first4=Erasmo C. |last5=Hay |first5=Cameron H. |date=February 2020 |editor-last=Buschmann |editor-first=A. |title=The Biogeographic Importance of Buoyancy in Macroalgae: A Case Study of the Southern Bull-Kelp Genus Durvillaea (Phaeophyceae), Including Descriptions of Two New Species 1 |journal=Journal of Phycology |language=en |volume=56 |issue=1 |pages=23–36 |doi=10.1111/jpy.12939 |pmid=31642057 |s2cid=204850695 |issn=0022-3646|doi-access=free |bibcode=2020JPcgy..56...23F }}</ref> For ''[[Giant kelp|Macrocystis pyrifera]]'', adaptation of pneumatocysts and raft forming have made the species dispersal method so successful that the immense spread of coast in which the species can be found has been found to actually be very recently [[Colonization|colonized]]. This can be observed by the low genetic diversity in the [[subantarctic]] region.<ref>{{Cite journal |last1=Macaya |first1=E. C. |last2=Zuccarello |first2=G. C. |date=2010-12-16 |title=Genetic structure of the giant kelp Macrocystis pyrifera along the southeastern Pacific |journal=Marine Ecology Progress Series |language=en |volume=420 |pages=103–112 |doi-access=free |doi=10.3354/meps08893 |bibcode=2010MEPS..420..103M |issn=0171-8630}}</ref> Dispersal by rafts from buoyant species also explains some evolutionary history for non-buoyant species of kelp. Since these rafts commonly have hitchhikers of other diverse species, they provide a mechanism for dispersal for species that lack buoyancy. This mechanism has been recently confirmed to be the cause of some dispersal and evolutionary history for kelp species in a study done with [[Genomics|genomic analysis]].<ref>{{Cite journal |last1=Fraser |first1=Ceridwen I. |last2=McGaughran |first2=Angela |last3=Chuah |first3=Aaron |last4=Waters |first4=Jonathan M. |date=August 2016 |title=The importance of replicating genomic analyses to verify phylogenetic signal for recently evolved lineages |journal=Molecular Ecology |language=en |volume=25 |issue=15 |pages=3683–3695 |doi=10.1111/mec.13708 |pmid=27238591 |bibcode=2016MolEc..25.3683F |s2cid=206183570 |issn=0962-1083|hdl=11343/291926 |hdl-access=free }}</ref> Studies of kelp structure evolution have helped in the understanding of the adaptations that have allowed for kelp to not only be extremely successful as a group of organisms but also successful as an [[ecosystem engineer]] of [[kelp forest]]s, some of the most diverse and dynamic ecosystems on earth.

===Prominent species===
* Bull kelp, ''[[Nereocystis luetkeana]]'', a northwestern American species. Used by coastal [[Indigenous peoples of the Americas|indigenous peoples]] to create [[fishing net]]s.{{clarify|how were the nets made from kelp?|date=May 2025}}{{cn|date=May 2025}}
* Giant kelp, ''[[Macrocystis pyrifera]]'', the largest seaweed. Found in the [[Pacific]] coast of [[North America]] and [[South America]], and the Atlantic coast of [[South Africa]] (formerly ''[[Macrocystis angustifolia]]'').<ref name="Red book">Stegenga, H., Bolton, J.J., & Anderson, R.J. 1997. ''Seaweeds of the South African West Coast''. Contributions from the Bolus Herbarium, University of Cape Town. ISBN 0-7992-1793-X</ref> 
* [[Kombu#Prominent species|Kombu]], ''[[Saccharina japonica]]'' (formerly ''Laminaria japonica'') and others, several edible species of kelp found in [[Japan]].
*Golden V Kelp ([[Aureophycus]] aleuticus ) of the [[Aleutian Islands]].

Species of ''Laminaria'' in the British Isles;
* ''[[Laminaria digitata]]'' (Hudson) J.V. Lamouroux (Oarweed; Tangle)
* ''[[Laminaria hyperborea]]'' (Gunnerus) Foslie (Curvie)
* ''[[Laminaria ochroleuca]]'' Bachelot de la Pylaie
* ''[[Laminaria saccharina|Saccharina latissima]]'' (Linnaeus) J.V.Lamouroux (sea belt; sugar kelp; sugarwack)

Species of ''[[Laminaria]]'' worldwide, listing of species at [[AlgaeBase]]:<ref>[http://www.algaebase.org/search/genus/detail/?genus_id=Za1ced4073025c37b ''AlgaeBase Laminariales'']</ref>
* ''[[Laminaria agardhii]]'' (NE. [[Americas|America]])
<!--* ''[[Kombu|Laminaria angustata]]''→Saccharina longissima ([[Japan]])-->
* ''[[Laminaria bongardina]]'' Postels et Ruprecht (Bering Sea to [[California]])
* ''[[Laminaria cuneifolia]]'' (NE. America)
* ''[[Laminaria dentigera]]'' Klellm. (California - America)
* ''[[Laminaria digitata]]'' (NE. America)
* {{ill|Laminaria ephemera|ar|لاميناريا عابرة|arz|لاميناريا عابره|fr|Laminaria ephemera|species|Laminaria ephemera|italic=yes}} Setchell (Sitka, Alaska, to Monterey County, California - America)
* {{ill|Laminaria farlowii|ar|لاميناريا فرلوية|arz|لاميناريا فرلويه|fr|Laminaria farlowii|species|Laminaria farlowii|italic=yes}} Setchell (Santa Cruz, California, to Baja California - America)
* {{ill|Laminaria groenlandica|species|italic=yes}} (NE. America)
* {{ill|Laminaria longicruris|fr|Laminaria longicruris|species|Laminaria longicruris|italic=yes}} (NE. America)
* ''[[Laminaria nigripes]]'' (NE. America)
* ''[[Laminaria ontermedia]]'' (NE. America)
* ''[[Laminaria pallida]]'' Greville ex J. Agardh ([[South Africa]])<ref name="Red book" />
* {{ill|Laminaria platymeris|ar|لاميناريا مسطحة الأجزاء|species|Laminaria platymeris|italic=yes}} (NE. America)
* ''[[Laminaria saccharina]]'' (Linnaeus) Lamouroux, synonym of ''[[Saccharina latissima]]'' (north east Atlantic Ocean, Barents Sea south to Galicia - Spain)
* {{ill|Laminaria setchellii|ar|لاميناريا سيتشيلية|arz|لاميناريا سيتشيليه|fr|Laminaria setchellii|species|Laminaria setchellii|italic=yes}} Silva (Aleutian Islands, Alaska to Baja California America)
* ''[[Laminaria sinclairii]]'' (Harvey ex Hooker f. ex Harvey) Farlow, Anderson et Eaton (Hope Island, British Columbia to Los Angeles, California - America)
* {{ill|Laminaria solidungula|ar|لاميناريا أحادية الظلفة|species|Laminaria solidungula |italic=yes}} (NE. America)
* ''[[Laminaria stenophylla]]'' (NE. America)

[[File:Five-ribbed kelp (Costaria costata).jpg|thumb|''Costaria costata,'' five-ribbed kelp]]
Other species in the [[Laminariales]] that may be considered as kelp:
* ''[[Alaria esculenta]]'' (North Atlantic)<ref>{{cite web |title=Dabberlocks (Alaria esculenta) |url=https://www.marlin.ac.uk/species/detail/1291 |website=The Marine Life Information Network |access-date=1 August 2019}}</ref>
* ''[[Alaria marginata]]'' Post. & Rupr. (Alaska and California - [[Americas|America]])
* {{ill|Costaria costata|fr|Costaria costata|species|Costaria costata|italic=yes}} (C.Ag.) Saunders (Japan; Alaska, California - America)
* {{ill|Ecklonia brevipes|species|italic=yes}} J. Agardh  (Australia; New Zealand)
* ''[[Ecklonia maxima]]'' (Osbeck) Papenfuss (South Africa)<ref name="Red book" />
* ''[[Ecklonia radiata]]'' (C.Agardh) J. Agardh (Australia; Tasmania; New Zealand; South Africa)<ref name="Red book" />
* ''[[Eisenia arborea]]'' Aresch. (Vancouver Island, British Columbia, Montrey, Santa Catalina Island, California - America)
* ''[[Egregia menziesii]]'' (Turn.) Aresch.
* {{ill|Hedophyllum sessile|species|italic=yes}} (C.Ag.) Setch (Alaska, California - America)
* ''[[Macrocystis pyrifera]]'' (Linnaeus, C.Agardh) (Australia; Tasmania and South Africa)
* ''[[Pleurophycus gardneri]]'' Setch. & Saund. (Alaska, California - America)
* ''[[Pterygophora californica]]'' Rupr. (Vancouver Island, British Columbia to Bahia del Ropsario, Baja California and California - America)

Non-Laminariales species that may be considered as kelp:
* ''[[Durvillea antarctica]]'', [[Fucales]] ([[New Zealand]], [[South America]], and [[Australia]])
* ''[[Durvillea willana]]'', Fucales (New Zealand)
* ''[[Durvillaea potatorum]]'' ([[Jacques Labillardière|Labillardière]]) Areschoug, Fucales ([[Tasmania]]; Australia)

[[File:KelpforestI2500ppx.JPG|thumb|upright=1.14|A kelp forest]]
[[File:Anemone and seastar in kelp forest.jpg|thumb|upright=.7|Anemone and seastar in kelp forest]]