| Genus: |
Kadakia Raf., 1837 → Genus: 
Pontederia L., 1753 |
| Genus: |
Kadsura Juss., 1810 |
| Species: |
Kadsura japonica (L.) Dunal, 1817 |
| Genus: |
Kailosocarpus Hu, 1957 → Section: 
Camellia sect. Heterogenea Sealy, 1958 |
| Genus: |
Kalabotis Raf., 1837 → Genus: 
Allium L., 1753 |
| Species: |
Kalabotis flavum (L.) Raf., 1837 → Species: 
Allium flavum L., 1753 |
| Species: |
Kalabotis moly (L.) Raf. → Species: 
Allium moly L., 1753 |
| Genus: |
Kalaharia Baill., 1891 → Genus: 
Clerodendrum L., 1753 |
| Genus: |
Kalanchoe Adans., 1763 |
| Species: |
Kalanchoe beharensis Drake, 1903 |
| Variety: |
Kalanchoe beharensis var. aureo-aeneus Jacobsen → Species:
Kalanchoe beharensis Drake, 1903 |
| Variety: |
Kalanchoe beharensis var. subnuda Jacobsen → Species:
Kalanchoe beharensis Drake, 1903 |
| Species: |
Kalanchoe daigremontiana Raym.-Hamet & H.Perrier, 1914 |
| Species: |
Kalanchoe millotii Raym.-Hamet & H.Perrier, 1912 |
| Section: |
Kalanchoe sect. Bryophyllum (Salisb.) Mannoni & Boiteau |
| Section: |
Kalanchoe sect. Eukalanchoe Mannoni & Boiteau → Section: 
Kalanchoe sect. Kalanchoe |
| Section: |
Kalanchoe sect. Kalanchoe |
| Subgenus: |
Kalanchoe subgen. Bryophyllum (Salisb.) Koord., 1918-1920 → Section:
Kalanchoe sect. Bryophyllum (Salisb.) Mannoni & Boiteau |
| Subgenus: |
Kalanchoe subgen. Kalanchoe → Section:
Kalanchoe sect. Kalanchoe |
| Species: |
Kalanchoe tomentosa Baker, 1882 |
| Species: |
Kalanchoe van-tieghemii Raym.-Hamet, 1906 → Species:
Kalanchoe beharensis Drake, 1903 |
| Subfamily: |
Kalanchoideae A.Berger in Engl. & Prantl, 1930 |
| Superfamily: |
Kalenteroidea † Marwick, 1953 |
| Genus: |
Kalmia L., 1753 |
| Species: |
Kalmia latifolia L., 1753 |
| Cultivar: |
Kalmia latifolia 'Minuet' |
| Genus: |
Kalonymus (Beck) Prokh., 1949 → Subgenus: Euonymus subgen. Kalonymus Beck, 1892 |
| Genus: |
Kalopanax Miq., 1863 |
| Species: |
Kalopanax pictus (Thunb.) Nakai → Species: 
Kalopanax septemlobus (Thunb.) Koidz., 1925 |
| Species: |
Kalopanax septemlobus (Thunb.) Koidz., 1925 |
| Genus: |
Kampmannia Steud., 1853 → Genus: 
Cortaderia Stapf, 1897 |
| Family: |
Kaniaceae Nakai → Subfamily: 
Myrtoideae Sweet, 1827 |
| Genus: |
Kanopikon Raf., 1838 → Genus: 
Euphorbia L., 1753 |
| Genus: |
Kantemon Raf., 1836 → Genus: 
Lonicera L., 1753 |
| Genus: |
Karkandela Raf., 1838 → Genus: 
Musa L., 1753 |
| Nothospecies: |
Karkandela × malabarica Raf., 1838 → Nothospecies: 
Musa × paradisiaca L., 1753 |
| Domain: |
Karyonta Novák, 1930 → Domain: 
Eukaryota (Chatton, 1925) Whittaker & Margulis, 1978 |
| Genus: |
Katubala Adans., 1763 → Genus: 
Canna L., 1753 |
| Genus: |
Keitia Regel, 1878 → Genus: 
Gladiolus Tourn. ex L., 1753 |
| Species: |
Kemelia japonica (L.) Raf. → Species: 
Camellia japonica L., 1753 |
| Genus: |
Kengyilia C.Yen & J.L.Yang, 1990 → Genus: Elymus L., 1753 |
| Species: |
Kentia australis auct. → Species: 
Howea forsteriana (C.Moore & F.Muell.) Becc., 1877 |
| Species: |
Kentia forsteriana C.Moore & F.Muell. → Species:
Howea forsteriana (C.Moore & F.Muell.) Becc., 1877 |
| Genus: |
Kentranthus Neck., 1790 → Genus: 
Centranthus Neck. ex Lam. & DC., 1805 |
| Species: |
Kentranthus ruber Druce, 1897 → Species: 
Centranthus ruber (L.) DC. in Lam. & DC., 1805 |
| Species: |
Kentrophyllum baeticum Boiss. & Reut., 1852 → Species: 
Carthamus lanatus L., 1753 |
| Species: |
Kentrophyllum lanatum (DC.) Duby, 1828 → Species:
Carthamus lanatus L., 1753 |
| Genus: |
Kentrosiphon N.E.Br., 1932 → Genus:
Gladiolus Tourn. ex L., 1753 |
| Genus: |
Kepa Tourn. ex Raf., 1837 → Subgenus: 
Allium subgen. Cepa (Mill.) Radić, 1990 |
| Species: |
Kepa esculenta Raf., 1837 → Species: 
Allium cepa L., 1753 |
| Genus: |
Keraselma Neck. ex Juss. in F.Cuvier, 1822 → Subgenus: 
Euphorbia subgen. Esula Pers., 1806 |
| Species: |
Keraselma cyparissias (L.) Raf., 1838 → Species: 
Euphorbia cyparissias L., 1753 |
| Species: |
Keraselma oleracea (Pers.) Raf., 1838 → Species: Euphorbia peplus L., 1753 |
| Species: |
Keraselma peplus (L.) Raf., 1838 → Species: Euphorbia peplus L., 1753 |
| Species: |
Keraselma reniformis Raf., 1840 → Species: Euphorbia peplus L., 1753 |
| Genus: |
Keratolepis Rose ex Fröd., 1936 → Genus: 
Sedum L., 1753 |
| Species: |
Keratophytes retiformis † (von Schlotheim, 1816) → Species: 
Fenestella retiformis † (Schlotheim, 1816) |
| Genus: |
Kernera Willd., 1806 → Genus: Posidonia K.D.Koenig, 1805 |
| Species: |
Kernera oceanica (L.) Willd., 1806 → Species: Posidonia oceanica (L.) Delile, 1813 |
| Genus: |
Kerria DC., 1818 |
| Species: |
Kerria japonica (L.) DC., 1818 |
| Cultivar: |
Kerria japonica 'Pleniflora' |
| Variety: |
Kerria japonica var. denticulata L.C.Wang & X.G.Sun → Species:
Kerria japonica (L.) DC., 1818 |
| Variety: |
Kerria japonica var. typica Makino, 1914; non Nakai → Species:
Kerria japonica (L.) DC., 1818 |
| Tribe: |
Kerrieae Focke, 1888 |
| Supertribe: |
Kerriodae D.Potter, S.H.Oh & K.R.Robertson, 2007 |
| Genus: |
Ketmia Mill., 1754 → Genus: 
Hibiscus L., 1753 |
| Species: |
Ketmia arborea Moench, 1794 → Species: 
Hibiscus syriacus L., 1753 |
| Species: |
Ketmia mutabilis Moench, 1794 → Species: 
Hibiscus mutabilis L., 1753 |
| Species: |
Ketmia syriaca (L.) Scop., 1772 → Species:
Hibiscus syriacus L., 1753 |
| Species: |
Ketmia syrorum Medik., 1787 → Species:
Hibiscus syriacus L., 1753 |
| Genus: |
Khaya A.Juss., 1830 |
| Genus: |
Kickxia Dumort., 1827 |
| Species: |
Kickxia spuria (L.) Dumort., 1827 |
| Genus: |
Kierschlegeria Spach, 1835 → Genus: 
Fuchsia L., 1753 |
| Family: |
Kiggelariaceae Link, 1831 → Family: Achariaceae Harms, 1897 |
| Genus: |
Kimberella † Wade, 1972 |
| Genus: |
Kinabaluchloa K.M.Wong, 1993 → Genus: 
Bambusa Schreb., 1789 |
| Genus: |
Kinetostigma Dammer, 1905 → Genus: 
Chamaedorea Willd., 1806 |
| Genus: |
Kingsboroughia Liebm., 1850 → Genus: 
Meliosma Blume, 1823 |
| Genus: |
Kinostemon Kudô, 1929 → Genus: 
Teucrium L., 1753 |
| Family: |
Kirengeshomaceae Nakai, 1943 → Family: 
Hydrangeaceae Dumort., 1829 |
| Genus: |
Kirpicznikovia Á.Löve & D.Löve, 1976 → Genus: Rhodiola L., 1753 |
| Genus: |
Kirschlegera Rchb., 1841 → Genus:
Fuchsia L., 1753 |
| Genus: |
Kitamuraea Rauschert, 1982 → Genus: 
Aster L., 1753 |
| Genus: |
Kitamuraster Soják, 1982 → Genus:
Aster L., 1753 |
| Genus: |
Kitchingia Baker, 1881 → Genus:
Kalanchoe Adans., 1763 |
| Species: |
Kitchingia mandrakensis → Species:
Kalanchoe beharensis Drake, 1903 |
| Species: |
Kleinia quadricolor Crantz, 1766 → Species: Quisqualis indica L., 1762 |
| Genus: |
Knafia Opiz, 1852 → Genus: 
Salix L., 1753 |
| Genus: |
Knautia L., 1753 |
| Species: |
Knautia arvensis (L.) Coult., 1823 |
| Genus: |
Knifa Adans., 1763 → Genus: 
Hypericum Tourn. ex L., 1753 |
| Genus: |
Kniffa Vent., 1799 → Genus:
Hypericum Tourn. ex L., 1753 |
| Genus: |
Kniphofia Moench, 1794 |
| Species: |
Kniphofia caulescens Baker, 1872 |
| Species: |
Kniphofia hirsuta Codd, 1966 |
| Species: |
Kniphofia macowanii Baker, 1874 → Species: 
Kniphofia triangularis Kunth, 1843 |
| Species: |
Kniphofia rufa Baker, 1900 |
| Species: |
Kniphofia triangularis Kunth, 1843 |
| Species: |
Kniphofia uvaria (L.) Oken, 1841 |
| Genus: |
Knowlesia Hassk., 1866 → Genus: 
Tradescantia Ruppius ex L., 1753 |
| Genus: |
Knowltonia Salisb., 1796 → Genus: 
Anemone L., 1753 |
| Genus: |
Kobiosis Raf., 1840 → Genus:
Euphorbia L., 1753 |
| Genus: |
Kobresia Willd., 1805 → Genus: 
Carex L., 1753 |
| Family: |
Kobresiaceae Gilly → Subfamily: 
Cyperoideae Kostel., 1831 |
| Genus: |
Kobus A.Smith, 1840 |
| Genus: |
Kobus Kaempf. ex Salisb., 1807 → Genus: 
Magnolia L., 1753 |
| Species: |
Kobus leche Gray, 1850 |
| Genus: |
Koddampuli Adans., 1763 → Genus: 
Garcinia L., 1753 |
| Genus: |
Koehneago Kuntze, 1891 → Genus: 
Hoffmannia Sw., 1788 |
| Species: |
Koeleria dactylis Chaub. in Bory & Chaub., 1838 → Species: 
Dactylis glomerata L., 1753 |
| Tribe: |
Koelerieae Schur, 1866 → Tribe: 
Poeae R.Br., 1814 |
| Subtribe: |
Koeleriinae Asch. & Graebn., 1900 → Subtribe: 
Aveninae J.Presl in C.Presl, 1830 |
| Genus: |
Koellea Biria, 1811 → Genus: 
Eranthis Salisb., 1807 |
| Species: |
Koellea hyemalis (L.) Biria, 1811 → Species: 
Eranthis hyemalis (L.) Salisb., 1807 |
| Genus: |
Koelreuteria Laxm., 1772 |
| Species: |
Koelreuteria apiculata Rehder & E.H.Wilson, 1914 → Species: 
Koelreuteria paniculata Laxm., 1772 |
| Species: |
Koelreuteria paniculata Laxm., 1772 |
| Genus: |
Kolerma Raf., 1840 → Genus:
Carex L., 1753 |
| Genus: |
Kolowratia C.Presl, 1827 → Genus: 
Alpinia Roxb., 1810; non L., 1753 |
| Genus: |
Komana Adans., 1763 → Genus:
Hypericum Tourn. ex L., 1753 |
| Species: |
Komana patula (Thunb. ex Murray) Y. Kimura ex Honda, 1939 → Species: 
Hypericum patulum Thunb. in Murray, 1784 |
| Genus: |
Konig Adans., 1763 → Genus: 
Lobularia Desv., 1815 |
| Species: |
Koniga maritima (L.) R.Br. in Denham & Clapperton, 1826 → Species: 
Lobularia maritima (L.) Desv., 1815 |
| Genus: |
Korolkowia Regel, 1873 → Genus: 
Fritillaria Tourn. ex L., 1753 |
| Genus: |
Krainzia Backeb., 1938 → Genus: 
Mammillaria Haw., 1812 |
| Species: |
Krainzia bocasana (Poselg.) Doweld, 2000 → Species: Mammillaria bocasana Poselg., 1853 |
| Species: |
Krainzia elongata (DC.) Doweld, 2000 → Species: 
Mammillaria elongata DC., 1828 |
| Section: |
Krainzia sect. Leptocladodae (Lem.) Doweld, 2000 → Series: 
Mammillaria ser. Leptocladodae Lem. ex K.Schum., 1896 |
| Section: |
Krainzia sect. Stylothelae (Pfeiff.) Doweld, 2000 → Series: 
Mammillaria ser. Stylothelae (Pfeiff.) K.Schum., 1898 |
| Genus: |
Krapfia DC., 1818 → Genus: 
Ranunculus L., 1753 |
| Species: |
Kraunhia floribunda (Willd.) Taub. in Engl. & Prantl, 1894 → Species: Wisteria floribunda (Willd.) DC., 1825 |
| Species: |
Kraunhia sinensis (Sims) Makino, 1910 → Species: 
Wisteria sinensis (Sims) Sweet, 1826 |
| Genus: |
Kremeria Durieu, 1846 → Genus: 
Leucanthemum Mill., 1754 |
| Genus: |
Kretania Beuret, 1959 → Genus: Polyommatus Latreille, 1804 |
| Species: |
Kroenleinia grusonii (Hildm.) Lodé, 2014 → Species: 
Echinocactus grusonii Hildm., 1886 |
| Genus: |
Kromon Raf., 1837 → Genus:
Allium L., 1753 |
| Genus: |
Kuekenthalia Börner, 1912 → Genus:
Carex L., 1753 |
| Genus: |
Kuestera Regel, 1857 → Genus: 
Justicia L., 1753 |
| Genus: |
Kumara Medik., 1786 → Genus: 
Aloe L., 1753 |
| Genus: |
Kumlienia Greene, 1886 → Genus:
Ranunculus L., 1753 |
| Genus: |
Kunthea Humb. & Bonpl. → Genus:
Chamaedorea Willd., 1806 |
| Genus: |
Kunthia Humb. & Bonpl., 1809 → Genus:
Chamaedorea Willd., 1806 |
| Species: |
Kunthia deppii Zucc., 1834 → Species: 
Chamaedorea elegans Mart., 1830 |
| Genus: |
Kurrimia Wall. ex Meisn., 1837 → Genus: 
Itea L., 1753 |
| Genus: |
Kyllinga Rottb., 1773 → Genus: 
Cyperus L., 1753 |