Phylum (Plantae): Ochrophyta

Ochrophyta is a group of mostly photosynthetic heterokonts. Their plastid is of red algal origin.

The classification of the group is still being worked out. Some authors (e.g., Cavalier-Smith) divide it into two subphyla, Phaeista Cavalier-Smith 1995 (comprising Hypogyristea and Chrysista in some classifications, or Limnista and Marista in others) and Khakista Cavalier-Smith, 2000 (comprising Bolidomonas and diatoms). Others prefer not to use the subphyla, listing only lower taxa (e.g., Reviers, 2002, Guiry & Guiry, 2014).

Reference: Wikipedia

Phylum (Plantae): Ochrophyta

The brown seaweeds have recently been grouped into a single large division (=phylum) with other unicellular golden or brown-pigmented algae (e.g. diatoms, chrysophytes). This is based on the fine structure of their flagella and chloroplasts, among other characteristics. Brown seaweeds possess an accessory photosynthetic pigment called fucoxanthin, which gives them their golden-brown color. These large, productive seaweeds are important components of nearshore marine communities, especially in temperate latitudes. The kelps (Order Laminariales, including Macrocystis) have a complex life history that alternates between a large spore-producing phase and a microscopic gamete-producing stage. 1500-2000 living species.

Reference: seanet.stanford.edu