Ochrophyte

Ochrophytes Temporal range: Middle Proterozoic[1] 1000–0 Ma Pha. Proterozoic Archean Had.
Dense kelp forest with understory at Partridge Point near Dave's Caves, Cape Peninsula
Scientific classification
Domain:	Eukaryota
Clade:	Diaphoretickes
Clade:	SAR
Clade:	Stramenopiles
Phylum:	Gyrista
Subphylum:	Ochrophytina Cavalier-Smith 1986 emend. 1996[2]
Type genus
Fucus Linnaeus, 1753
Classes[4]
Chrysista Chrysophyceae Eustigmatophyceae Picophagea Raphidophyceae Aurearenophyceae Phaeothamniophyceae Chrysomerophyceae Chrysoparadoxophyceae Phaeosacciophyceae Phaeophyceae Schizocladiophyceae Xanthophyceae Olisthodiscophyceae[3] Diatomista Dictyochophyceae Pelagophyceae Bolidophyceae Diatomeae Incertae sedis: Actinophryida
Diversity
23,314 described species[5] >100,000 estimated species[6]
Synonyms
Heterokontophyta Guiry, R.A.Andersen & Moestrup 2023[7] Ochrista Cavalier-Smith 1986[8][9] Stramenochromes Leipe et al. 1994[9]

Ochrophytes, also known as heterokontophytes or stramenochromes, are a group of algae. They are the photosynthetic stramenopiles, a group of eukaryotes, organisms with a cell nucleus, characterized by the presence of two unequal flagella, one of which has tripartite hairs called mastigonemes. In particular, they are characterized by photosynthetic organelles or plastids enclosed by four membranes, with membrane-bound compartments called thylakoids organized in piles of three, chlorophyll a and c as their photosynthetic pigments, and additional pigments such as β-carotene and xanthophylls. Ochrophytes are one of the most diverse lineages of eukaryotes, containing ecologically important algae such as brown algae and diatoms. They are classified either as phylum Ochrophyta or Heterokontophyta, or as subphylum Ochrophytina within phylum Gyrista. Their plastids are of red algal origin.