• ×Anthematricaria dominii Rohlena: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• ×Anthemimatricaria inolens P.Fourn.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• ×Anthemimatricaria maleolens P.Fourn.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• ×Anthemimatricaria sulfurea P.Fourn.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• ×Argyrautia degeneri Sherff: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• ×Carduogalactites ludoviciae (Bertr.) P.Fourn.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• ×Cirsio-carduus cirsiformis (Vuk.) Arènes: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• ×Cirsio-carduus hohenackeri Arènes: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• ×Cirsio-carduus jaubertianus (Sennen & Septimin) Arènes: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• ×Cirsio-carduus lutetianus Arènes: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• ×Cirsio-carduus parisiensis P.Fourn.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• ×Crepi-Hieracium garnieri (Petitm.) P.Fourn.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• ×Filfia mixta (Holuby) Holub: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• ×Solidaster lutens M.L.Green: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• ×Solidaster luteus (Everett) M.L.Green ex Dress: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Aaronsohnia factorovskyi Warb. & Eig: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Aaronsohnia pubescens (Desf.) K.Bremer & Humphries: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Aataenia reticularis Gnilovskaja, 1976 †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abacella cornuta Shuysky, 1973 †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abacella delicatula J.H.Johnson, 1964 †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abacella dentata Shuysky, 1973 †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abacella pertusa Maslov, 1956 †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abacella pustulata Shuysky, 1973 †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abacella stellata Shuysky, 1991 †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abbottella concinna Hollenberg, 1967: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abedinium dasypus (Cachon & Cachon-Enjumet) Loeblich Jr & Loeblich III, 1966: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abelspora portucalensis Azevedo, 1987: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abies alba Mill.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abildgaardia fusiformis (Wangwasit & D.A.Simpson) Larridon: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abildgaardia macrantha (Boeckeler) Goetgh.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abildgaardia mexicana (Palla) Kral: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abildgaardia odontocarpa (S.T.Blake) K.L.Wilson & J.J.Bruhl: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abildgaardia ovata (Burm.f.) Kral: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abildgaardia oxystachya (F.Muell.) K.L.Wilson & J.J.Bruhl: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abildgaardia pachyptera (S.T.Blake) K.L.Wilson & J.J.Bruhl: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abildgaardia schoenoides R.Br.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abildgaardia triflora (L.) Abeyw.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abratopdinium cardioforme S.Mao & B.A.R.Mohr †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abratopdinium kerguelense S.Mao & B.A.R.Mohr †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella caespitosa Petrie ex Kirk: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella diemii Cabrera: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella emarginata (Gaudich.) Cass.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella fertilis Swenson: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella inconspicua Hook.f.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella linearifolia A.Gray: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella linearis Berggr.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella muscosa Kirk: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella nivigena (F.Muell.) F.Muell. ex Benth.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella patearoa Heads: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella purpurea Swenson: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella pusilla (Hook.f.) Hook.f.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella rostrata Swenson: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella rosulata (Hook.f.) Hook.f.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella spathulata (Hook.f.) Hook.f.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella submarginata A.Gray: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella trichoachaenia Cabrera: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abrotanella trilobata Swenson: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abroteia suborbicularis (Harvey) J.Agardh, 1878: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abruptophycus compositus Vologdin, 1962 †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Absconditella antarctica Søchting & Vězda, 2004: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Absidia spinosa Lendn., 1905: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abutilon theophrasti Medik.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Abyssomyces hydrozoicus Kohlm., 1970: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acaciella angepena W.V.Preiss, 1972 †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acaciella augusta W.V.Preiss, 1972 †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acaciella australica (Howchin) M.R.Walter, 1972 †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acaciella savoryensis K.Grey & M.R.Walter, 1994 †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acalypha wilkesiana Müll. Arg.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acamptopappus shockleyi A.Gray: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acamptopappus sphaerocephalus (Harv. & A.Gray) A.Gray: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthina bullosa Korde, 1973 †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthina multiformis Korde, 1973 †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthocephalus amplexifolius Kar. & Kir.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthocephalus benthamianus Regel: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthocereus tetragonus (Linnaeus) Hummelinck, 1938: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthochloris bacillifera Pascher, 1938: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthochloris brevispinosa Pascher, 1930: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthochloris ingens Margalef, 1956: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthochloris scherffelii Pascher, 1938: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthochloris verrucosa Ettl, 1977: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthocladium dockeri F.Muell.: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthococcus antarcticus Hooker f. & Harvey, 1845: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthodesmos distichus C.D.Adams & duQuesnay: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthodinium caryophyllum Kofoid, 1907: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthogonyaulax acanthosphaera (Sargeant) Sargeant †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthogonyaulax paliuros (Sargeant) Sargeant †: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthogonyaulax spinifera (Murray & Whitting) H.W.Graham, 1942: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthoica acanthifera Lohmann ex Lohmann, 1913: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthoica acanthos J.Schiller, 1925: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthoica bidentula Lecal-Schlauder, 1951: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthoica biscayensis A.Kleijne, 1992: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthoica coronata Lohmann, 1903: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthoica janchenii J.Schiller, 1925: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthoica lithostratos J.Schiller, 1926: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthoica maxima Heimdal, 1981: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthoica monospina J.Schiller, 1925: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthoica ornata Conrad, 1928: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthoica quattrospina Lohmann, 1903: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthoica rubens Kamptner, 1941: The International Code of Nomenclature for algae, fungi, and plants (ICN)
• Acanthoica schilleri Conrad, 1928: The International Code of Nomenclature for algae, fungi, and plants (ICN)