Leathesia marina

{{Short description|Species of seaweed}}

{{Speciesbox

| image = Leathesia_difformis.jpg

| taxon = Leathesia marina

| synonyms = Leathesia difformis

| authority = (Lyngbye]]) Decaisne

}}

Leathesia marina (Lyngbye) Decaisne, 1842, previously known as Leathesia difformis Areschoug, 1847, commonly known as the sea cauliflower the sea potato, and brown brains is a species of littoral brown algae in the class Phaeophyceae and the order Ectocarpales, Guiry, M.D. & Guiry, G.M. (2023). AlgaeBase. World-wide electronic publication, National University of Ireland, Galway (taxonomic information republished from AlgaeBase with permission of M.D. Guiry). Leathesia difformis Areschoug, 1847. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=144953 on 2023-10-14 which is commonly attached to other seaweeds and sometimes rocks. When young, the organism is solid but as it matures it becomes hollow and somewhat convoluted and has the appearance of a small leathery brown bag about the same size as a tennis ball. The texture is rubbery and the outer surface smooth.{{Citation needed|date=February 2012}}

These brain-like brown seaweeds can be found growing on rock or as epiphytes on other seaweeds in the mid to low intertidal. Individuals can grow to ~{{convert|15|cm}} in diameter. Young individuals can resemble other globular forms of algae, such as Soranthera ulvoidea.{{cite web|last1=Lindeberg|first1=Mandy|last2=Lindstrom|first2=Sandra|title=Studded Sea Balloons Soranthera ulvoidea|url=http://www.seaweedsofalaska.com/species.asp?SeaweedID=54|website=Seaweeds of Alaska|accessdate=5 May 2018|language=English}}{{cite journal|last1=Cho|first1=Ga Youn|last2=Kim|first2=Myung-Sook|last3=Boo|first3=Sung Min|title=Phylogenetic Relationships of Soranthera ulvoidea (Chordariaceae, Phaeophyceae) on the Basis of Morphology and Molecular Data|journal=Algae|date=6 January 2005|volume=20|issue=2|pages=91–97|doi=10.4490/ALGAE.2005.20.2.091|url=https://www.researchgate.net/publication/264168388|accessdate=24 May 2018|language=English|format=PDF|issn=1226-2617|oclc=4663643362|doi-access=free}} To determine if it is Leathesia, squeeze and flatten a piece between your fingers. Leathesia will break apart into filaments whereas other globular forms will flatten but remain intact.[http://www.beachwatchers.wsu.edu/ezidweb/seaweeds/Leathesia.htm "Leathesia difformis"] {{Webarchive|url=https://web.archive.org/web/20100531192248/http://beachwatchers.wsu.edu/ezidweb/seaweeds/Leathesia.htm |date=2010-05-31 }}, 18 December 2006. Retrieved on 8 February 2012.{{cite web|last1=Holmeson|first1=Jan|title=Soranthera ulvoides (Studded sea balloon)|url=https://soundwaterstewards.org/ezidweb/seaweeds/Soranthera.htm|website=Sound Water Stewards|publisher=Periwinkle Press|accessdate=5 May 2018|location=Oak Harbor, WA|language=English|date=19 December 2006}}