{{Short description|Order of algae}} {{Automatic taxobox | image = Ulothrix zonata 469984861.jpg | image_alt = Ulothrix zonata | image_caption = ''Ulothrix zonata'' | taxon = Ulotrichales | authority = Borzì | subdivision_ranks = Families | subdivision_ref = <ref name=AlgaeBase>{{AlgaeBase genus | id=4566 | title=Ulotrichales Borzì | access-date=2026-03-26 }}</ref> | subdivision = See text | synonyms = Acrosiphoniales }}
'''Ulotrichales''' is an order of green algae in the class Ulvophyceae.<ref>See the NCBI [https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=31306 webpage on Ulotrichales]. Data extracted from the {{cite web | url=https://ftp.ncbi.nih.gov/pub/taxonomy/ | title=NCBI taxonomy resources | publisher=National Center for Biotechnology Information | access-date=2007-03-19}}</ref> Members of this order are most common in freshwater and marine habitats, although some are terrestrial or aerophytic.<ref name=Skaloud/>
Algae in the Ulotrichales are diverse in morphology, and include coccoid (round single cells), sarcinoid (three-dimensional packet-like), filamentous (thread-like), and blade-like forms. The cells generally contain a single parietal chloroplast with one to several pyrenoids, and one or several nuclei.<ref name=Skaloud>{{cite book | last1 = Škaloud | first1 = Pavel | last2 = Rindi | first2 = Fabio | last3 = Boedeker | first3 = Christian | last4 = Leliaert | first4 = Frederik | title = Chlorophyta: Ulvophyceae | series = Süßwasserflora von Mitteleuropa | volume = 13 | publisher = Springer Spektrum | location = Berlin, Germany | year = 2018 | isbn = 978-3-662-55494-4 | doi = 10.1007/978-3-662-55495-1 | url = https://link.springer.com/book/10.1007/978-3-662-55495-1 | pages=i-x, 1–289 }}</ref>
Some algae in the Ulotrichales are diplohaplontic; in these algae the gametophyte stage is dominant and the sporophyte consists of a single club-shaped to spherical, attached zygote. This zygote is known as the ''Codiolum'' stage.<ref name=Skaloud/> In other Ulotrichales, sexual reproduction is unknown.<ref name=Skaloud/>
==Families== {{Div col|colwidth=15em}} * †Anatoliporaceae * Binucleariaceae * Collinsiellaceae * Gayraliaceae * Gloeotilaceae * Gomontiaceae * Hazeniaceae * Helicodictyaceae * Kraftionemaceae * Monostromataceae * Planophilaceae * Sarcinofilaceae * Tupiellaceae * Ulotrichaceae * †Vermiporellaceae {{Div col end}}
Genera unplaced to family (''incertae sedis''):<ref name=AlgaeBase/> *''Caulinema'' *''Trichosarcina''
==References== {{Reflist|1}}
{{Taxonbar|from=Q855962}} {{Authority control}}
Category:Ulotrichales Category:Chlorophyta orders
{{Ulvophyceae-stub}}