| Melanthiaceae | |
Zigadenus acutus
| Rydb. | Bull. Torrey Bot. Club 27(10): 536 | 1900 |
| Melanthiaceae | * |
Zigadenus alpinus
| Gand. | Bull. Soc. Bot. France 66(7): 293 | 1919 [1920] |
| Melanthiaceae | |
Zigadenus alpinus
| Blank. | Sci. Stud. Montana Coll. Agric., Bot. 1(2): 44–45 | 1905 |
| Melanthiaceae | |
Zigadenus angustifolius
| (Michx.) S. Watson | Proc. Amer. Acad. Arts 14: 280 | 1879 |
| Melanthiaceae | |
Zigadenus bracteatus
| (Sims) Sweet | Hort. Brit. 429 | 1826 |
| Melanthiaceae | |
Zigadenus brevibracteatus
| (M.E. Jones) H.M. Hall | Univ. Calif. Publ. Bot. 6(7): 165 | 1915 |
| Melanthiaceae | |
Zigadenus canadensis
| Baker | J. Linn. Soc., Bot. 17: 482 | 1879 |
| Melanthiaceae | |
Zigadenus chloranthus
| Richardson | Narr. Journey Polar Sea 736 | 1823 |
| Melanthiaceae | |
Zigadenus coloradoensis
| Rydb. | Bull. Torrey Bot. Club 27(10): 534–535 | 1900 |
| Melanthiaceae | |
Zigadenus commutatus
| Schult. & Schult. f. | Syst. Veg. (ed. 15 bis) 7(2): 1560 | 1830 |
| Melanthiaceae | |
Zigadenus densus
| (Desr.) Fernald | Rhodora 42(499): 254 | 1940 |
| Melanthiaceae | |
Zigadenus diegoensis
| Davidson | Bull. S. Calif. Acad. Sci. 23(3): 105 | 1924 |
| Melanthiaceae | |
Zigadenus dilatatus
| Greene | Pl. Baker. 1: 51 | 1901 |
| Melanthiaceae | |
Zigadenus douglasii
| Torr. | Pacif. Railr. Rep. Parke, Bot. 7: 20 | 1857 |
| Melanthiaceae | |
Zigadenus elegans
| Pursh | Fl. Amer. Sept. 1: 241 | 1814 [1813] |
| Melanthiaceae | |
Zigadenus exaltatus
| Eastw. | Bot. Gaz. 41(4): 283–284 | 1906 |
| Melanthiaceae | |
Zigadenus falcatus
| Rydb. | Bull. Torrey Bot. Club 27(10): 536–537 | 1900 |
| Melanthiaceae | |
Zigadenus fontanus
| Eastw. | Leafl. W. Bot. 2(3): 41–42 | 1937 |
| Melanthiaceae | |
Zigadenus fremontii
| (Torr.) Torr. ex S. Watson | Botany (Fortieth Parallel) 343 | 1871 |
| Melanthiaceae | |
Zigadenus frigidus
| (Schltdl. & Cham.) D. Don | Edinburgh New Philos. J. 13(26): 233 | 1832 |
| Melanthiaceae | |
Zigadenus fuscatus
| Raf. | Fl. Tellur. 2: 30 | 1836 [1837] |
| Melanthiaceae | * |
Zigadenus glaberrimus
| Hook. & Arn. | Bot. Beechey Voy. 160 | 1841 [1833] |
| Melanthiaceae | |
Zigadenus glaberrimus
| Michx. | Fl. Bor.-Amer. 1: 214, pl. 22 | 1803 |
| Melanthiaceae | |
Zigadenus glaucus
| (Nutt.) Nutt. | J. Acad. Nat. Sci. Philadelphia 7(1): 56 | 1834 |
| Melanthiaceae | |
Zigadenus gracilentus
| Greene | Pittonia 4(24A): 241 | 1901 |
| Melanthiaceae | |
Zigadenus gramineus
| Rydb. | Bull. Torrey Bot. Club 27(10): 535 | 1900 |
| Melanthiaceae | |
Zigadenus hintoniorum
| B.L. Turner | Phytologia 72: 378 | 1992 |
| Melanthiaceae | ** |
Zigadenus hybridus
| Endl. ex Kunth | Enum. Pl. 4: 196 | 1843 |
| Melanthiaceae | |
Zigadenus intermedius
| Rydb. | Bull. Torrey Bot. Club 27(10): 535–536 | 1900 |
| Melanthiaceae | |
Zigadenus japonicus
| Miq. | Verslagen Meded. Afd. Natuurk. Kon. Akad. Wetensch., ser. 2 2: 88 – 89 | 1868 |
| Melanthiaceae | * |
Zigadenus japonicus
| Makino | Bot. Mag. (Tokyo) 17: 162 | 1903 |
| Melanthiaceae | |
Zigadenus leimanthoides
| (A. Gray) A. Gray | Manual (ed. 2) 476 | 1857 |
| Melanthiaceae | |
Zigadenus longus
| Greene | Pittonia 4(24): 240–241 | 1901 |
| Melanthiaceae | |
Zigadenus makinoanus
| (Makino) Miyabe & Kudô | Trans. Sapporo Nat. Hist. Soc. 5: 39 | 1914 |
| Melanthiaceae | |
Zigadenus mexicanus
| (Kunth) Hemsl. | Biol. Cent.-Amer., Bot. 3(18): 382 | 1885 |
| Melanthiaceae | |
Zigadenus micranthus
| Eastw. | Bull. Torrey Bot. Club 30(9): 483 | 1903 |
| Melanthiaceae | |
Zigadenus mogollonensis
| W.J. Hess & Sivinski | Sida 16(3): 390–393, f. 1 | 1995 |
| Melanthiaceae | |
Zigadenus mohinorensis
| Greenm. | Proc. Natl. Acad. Sci. U.S.A. 39: 71 | 1903 |
| Melanthiaceae | |
Zigadenus monoecus
| (Walter) Kunth | Enum. Pl. 4: 196 | 1843 |
| Melanthiaceae | |
Zigadenus muscitoxicus
| (Walter) Regel | | |
| Melanthiaceae | |
Zigadenus neglectus
| Espejo, López-Ferr. & Ceja | Acta Bot. Mex. 48: 47, f. 5 | 1999 |
| Melanthiaceae | |
Zigadenus nuttallii
| S. Watson ex A. Gray | Botany (Fortieth Parallel) 343 | 1871 |
| Melanthiaceae | |
Zigadenus paniculatus
| (Nutt.) S. Watson | Botany (Fortieth Parallel) 343 | 1871 |
| Melanthiaceae | |
Zigadenus porrifolius
| Greene | Bull. Torrey Bot. Club 8(11): 123 | 1881 |
| Melanthiaceae | |
Zigadenus sachalinensis
| F. Schmidt | Reis. Amur-Land., Bot. 188 | 1868 |
| Melanthiaceae | |
Zigadenus salinus
| A. Nelson | Bot. Gaz. 54(5): 406 | 1912 |
| Melanthiaceae | |
Zigadenus sibiricus
| (L.) A. Gray | Ann. Lyceum Nat. Hist. New York 4: 112 | 1857 |
| Melanthiaceae | |
Zigadenus speciosus
| Douglas ex Hook. | Fl. Bor.-Amer. 2: 177 | 1838 |
| Melanthiaceae | |
Zigadenus texensis
| (Rydb.) J.F. Macbr. | Contr. Gray Herb. 53: 4 | 1918 |
| Melanthiaceae | |
Zigadenus vaginatus
| (Rydb.) J.F. Macbr. | Contr. Gray Herb. 53: 4 | 1918 |
| Melanthiaceae | |
Zigadenus venenosus
| S. Watson | Proc. Amer. Acad. Arts 14: 279 | 1879 |
| Melanthiaceae | |
Zigadenus virescens
| (Kunth) J.F. Macbr. | Contr. Gray Herb. 53: 4 | 1918 |
| Melanthiaceae | |
Zigadenus virginicum
| (L.) Kunth | Syn. Pl. 4: 195 | 1843 |
| Melanthiaceae | * |
Zigadenus volcanicus
| S. Watson | Proc. Amer. Acad. Arts 18: 165 | 1883 |
| Melanthiaceae | ! |
Zigadenus volcanicus
| Benth. | Pl. Hartw. 96 | 1842 |
| Melanthiaceae | |
Zigadenus washakie
| A. Nelson | Univ. Wyoming Publ. Sci., Bot. 1(5): 124–126 | 1926 |