58 articles
Agar
Agar (agar-agar, E406, CAS 9002-18-0), kanten: polysaccharide of agarose and agaropectin from red algae (Gelidium, Gracilaria); gels at 34-43 °C, melts above 85 °C; used in food, culture media, and electrophoresis.
Algae
Algae: diverse photosynthetic organisms (including cyanobacteria, seaweeds, diatoms) across four kingdoms; 50,589 living species, 3-billion-year fossil record, primary producers, food and industrial uses, harmful blooms.
Algae fuel
Algae fuel, a third-generation biofuel from microalgae or kelp, was pursued by DOE's Aquatic Species Program from 1978; costs of $1.64 to over $30 per gallon and harvesting, drying, and extraction bottlenecks still limit commercialization.
Algal bloom
Algal bloom: rapid growth of algae or cyanobacteria in fresh or marine water; harmful algal blooms (HABs) produce toxins like microcystins, driven by nutrient pollution, warming, and stratification, exemplified by Lake Erie.
Alginic acid
Alginic acid (alginate, E 400, INS 400, CAS 9005-32-7) is a polysaccharide from brown seaweed, a copolymer of mannuronic and guluronic acid that gels with calcium by the egg-box model and is used as a thickener, gelling agent, and dental impression material.
Ascophyllum nodosum
Ascophyllum nodosum (knotted wrack, egg wrack, rockweed) is a North Atlantic brown fucoid seaweed of sheltered intertidal rocks, harvested for alginates, seaweed meal, fertilizers, and biostimulants.
Aulacoseira
Aulacoseira is a genus of freshwater centric diatoms, chain-forming algae with silica cell walls that are widespread and abundant in lakes and large rivers, with a fossil record reaching back to the Paleocene.
Botanical name
Botanical name: the formal scientific name of a plant, alga, or fungus under the ICN (formerly ICBN), a Linnaean binomial tied to a type specimen, governed by the Madrid Code of 2025.
Brown algae
Brown algae (Phaeophyceae) are multicellular marine seaweeds with chlorophyll a, c, and fucoxanthin; over 1,800 species including kelps, alginate- and fucoidan-rich cell walls, Ordovician origin, and major roles in kelp forests, food, and alginate production.
Chara (alga)
Chara (muskgrass, stonewort) is a genus of branched green macroalgae in Characeae, with calcium carbonate-encrusted gritty branches and a musky odor. It indicates oligotrophic hardwater quality, feeds waterfowl, and belongs to the Charales once deemed land plants' closest algal relatives.
Chlamydomonas
Chlamydomonas, especially Chlamydomonas reinhardtii, is a unicellular biflagellate green alga and model organism for photosynthesis, cilia, and the eyespot, with a 17-chromosome haploid genome and wide use in genetics and algal biotechnology.
Chlorella
Chlorella (クロレラ), a genus of unicellular green microalgae described by Beijerinck in 1890 with type species Chlorella vulgaris; cultivated since the 1960s as a protein-rich health food, feed, and biorefinery biomass with a robust cell wall.
Chlorophyta
Chlorophyta, the chlorophyte green algae, is one of two main green plant clades (with Streptophyta), diverging over 1 billion years ago; marine, freshwater, and terrestrial algae with chlorophyll a and b, prasinophyte origins, and core classes Chlorophyceae, Ulvophyceae, and Trebouxiophyceae.
Chondrus crispus
Chondrus crispus (Irish moss, carrageen moss) is a North Atlantic red alga, original source of carrageenan (E 407), a κ/λ mixture; edible, medicinal since centuries, harvested near 50,000 t in 1974, genome sequenced 2013.
Coccolithophore
Coccolithophore: unicellular haptophyte marine algae (about 200 species) covered in calcite coccolith plates; major calcifying phytoplankton driving the ocean carbonate pump, forming turquoise satellite-visible blooms, sensitive to ocean acidification.
Cyclotella
Cyclotella is a genus of centric diatoms, single-celled algae with silica cell walls, common in the phytoplankton of lakes and widely used as an indicator of lake environmental change.
Cylindrospermopsis raciborskii
Cylindrospermopsis raciborskii, now Raphidiopsis raciborskii, is a filamentous, nitrogen-fixing freshwater cyanobacterium that blooms in lakes and reservoirs and produces the toxins cylindrospermopsin or saxitoxin, having spread from tropical waters to every continent except Antarctica.
Diatom
Diatoms (Bacillariophyceae) are single-celled golden-brown algae with silica cell walls (frustules), 2–500 µm, 20,000 to 2 million estimated species, driving ~40% of oceanic carbon fixation and used in water monitoring and diatomite.
Edible seaweed
Edible seaweed: marine macroalgae such as nori, wakame, konbu, and gim eaten as food, rooted in East Asian cuisine, about 8 million tonnes used yearly, with iodine and cadmium safety limits and EU novel food rules.
Fragilaria
Fragilaria, established by Lyngbye in 1819, is a genus of araphid freshwater diatoms forming ribbon-shaped colonies, widely used in paleolimnology to reconstruct past lake conditions.
Gomphonema
Gomphonema is a large, abundant genus of freshwater diatoms of single-celled algae. Described by Ehrenberg in 1832, it has silica cell walls shaped like a wedge or club.
Green algae
Green algae: photosynthetic Chlorophyta and streptophyte algae of Viridiplantae with chlorophyll a and b, over a billion years old, and the streptophyte lineage ancestral to all land plants.
International Code of Nomenclature for algae, fungi, and plants
International Code of Nomenclature for algae, fungi, and plants (ICN, Botanical Code): rulebook for naming these organisms; current 18th edition is the Madrid Code (2025), superseding the Shenzhen Code (2018).
Kappaphycus alvarezii
Kappaphycus alvarezii, once known as Eucheuma cottonii and called elkhorn sea moss, is a tropical red alga farmed as the world's principal source of kappa-carrageenan, used in foods.
Kelp
Kelp (Laminariales): large brown algae of cool coastal waters, forming kelp forests on about 25% of the world's coastline. Includes giant kelp Macrocystis, bull kelp, kombu, alginate, blue carbon, urchin barrens, and global decline.
Kelp forest
Kelp forest: underwater ecosystems of large brown algae (Macrocystis, Nereocystis, Laminaria) on temperate rocky coasts, along 25% of world coastlines, threatened by urchin barrens and warming, valued at $684 billion yearly.
Kombu (昆布)
Kombu (昆布, konbu) is dried edible kelp, mainly Saccharina japonica, from Hokkaido; the base of dashi stock, source of umami discovered by Ikeda in 1908, and one of the richest food sources of iodine.
Laminaria digitata
Laminaria digitata (oarweed, tangle) is a North Atlantic brown kelp, type species of Laminaria, with digitate blades, ~1% dry-weight iodine, and Irish hatchery-based longline aquaculture for alginates and extracts.
List of green seaweeds of the Cape Peninsula and False Bay
The list of green seaweeds of the Cape Peninsula and False Bay covers green algae (Chlorophyta) recorded along the Peninsula's Atlantic coast and False Bay shores in South Africa.
Marimo (毬藻)
Marimo (毬藻), Aegagropila linnaei/brownii, is a freshwater green alga forming velvet-like lake balls, famous at Lake Akan, Japan, a Special Natural Monument, now endangered worldwide.