Waldsteinia idahoensis Piper, Bull. Torrey Bot. Club 30: 180. 1903
U.S.A.: Idaho, Idaho Co., along Lochia River, C.L. Hitchcock 24481, 1 July 1966, Topotype
Waltheria subcordata Standley, Contr. U.S. Nat. Herb. 18(3): 117-118. 1916
Columbia: Santa Marta, H.H. Smith 493, 1998-1901, ? Isotype
Warea sesilifolia Nash, Bull. Torr. Bot. Club 23: 101. 1896
U.S.A.: Florida, Nash Co., Bellair, G.V. Nash 2544, 3 Sept. 1895, Isotype
Wedelia heterophylla Rusby, Descriptions of Three Hundred New Species of South American Plants, pp. 152-153. 1920
Columbia: Santa Marta, H.H. Smith 515 (1898-1901), ? Isotype
Wedelia prostrata Hemsl. var. robusta Makino, Publication unknown
Japan: Satsuma Pref., T. Makino, 1932, ? Type Collection Material
Wedelia symmetrica Rusby, Descriptions of Three Hundred New Species of South American Plants, p. 153. 1920
Columbia: Santa Marta, H.H. Smith 1975 (1898-1901), ? Isotype
Weinmannia nervosa Killip, J. Wash. Acad. Sci. 16: 569. 1926
Columbia: Santa Marta, H.H. Smith 1743, 1898-1901, ? Isotype
Westringia angustifolia R.Br., Prod. Fl. Nov. Holl. 501. 1810
Australia: Dieman's Island, R. Brown, Type Collection Material
Westringia cinerea R.Br., Prodr. 151. 1830
Australia: South Coast, R. Brown, ? Isotype
Westringia dampieri R.Br., Prod. Fl. Nov. Holl. 501. 1810
Australia: R. Geoge's Sound, R. Brown, Type Collection Material
Westringia glabra R.Br., Prod. Fl. Nov. Holl. 501. 1810
Australia: East Coast, R. Brown, Type Collection Material
Westringia longifolia R.Br., Prod. Fl. Nov. Holl. 501. 1810
Australia: Port Jackson, R. Brown, Type Collection Material
Westringia rigida R.Br., Prod. Fl. Nov. Holl. 501. 1810
Australia: South Coast, R. Brown, Type Collection Material
Westringia rubiaefolia R.Br., Prod. Fl. Nov. Holl. 501. 1810
Australia: Van Diemen's Island, R. Brown, Type Collection Material
Wissadula fadyenii R.E. Fries, Kongl. Svenska Vetensk. Acad. Handl. 43: 30. 1908
Columbia: Santa Marta, H.H. Smith 496, 1898-1901, ? Isotype
Withania aristata Pauquy, De la Belladone 15. 1824 [1825]
Canary Islands: Tenerife, Santa Ursula, E. Asplund 599, 30 Mar. 1933, Topotype
Woodsia oregana D.C. Eaton var. squammosa Boivin, Nat. Can. 87: 49. 1960
Canada: Saskatchewan, Denare Beach, J.H. Hudson 1561, 19 Aug. 1954, Holotype
Woodsia scopulina D.C. Eaton ssp. laurentiana Windham
Canada: Ontario, Thunder Bay District, Crooks Twp., 1 km east of Cloud River bridge, C.E. Garton 18531, 12 Aug. 1978, Paratype
Woodsia scopulina D.C. Eaton var. laurentiana Windham, Contr. Univ. Mich. Herb. 19: 59. 1993
Canada: Ontario, Algonquin Park, N end of Hilliard Lake, D.M. Britton, 13 Aug. 1965, Paratype
Woodsia x tryonis Boivin, W. glabella R.Br. x ilvensis (L.) R.Br., Amer. Fern J. 38: 167. 1948; Nat. Can. 93: 273. 1966
Canada: Ontario, Thunder Bay District, Sibley Peninsula, N side of Thunder Mountain, Cody & Brown 21363, 11 July 1974 (DAO), Topotype
Woodwardia martinezii Maxon, Amer. Fern. J. 39: 88. 1949
Mexico: Hidalgo, near Zacualtipan, M. Martinez 27, 15 Apr. 1940, Isotype
Xanthium basilei Sennen, Bot. Soc. Arag. 11: 209. 1912
Spain: Catalogne, Barcelone à Can Tunis, F. Sennen 1493, 21 Sept. 1912, ? Type - Publication not Available
Xanthium chasei Fernald, Rhod. 48: 66.1946
U.S.A.: Illinois, East Peoria, V.H. Chase 10881, 17 Sept. 1949, Topotype
Xyris flabelliformis Chapm., Fl. S. U.S.A.: 499-500. 1860
U.S.A.: Florida, St. Augustine, F. Rugel 65, May 1848, Topotype, Type Collection Material?
Xyris smalliana Nash, Bull. Torrey Bot. Club 22: 159-160. 1895
U.S.A.: Florida, Lake Co., Eustis, Lake Ella, G.V. Nash 1585, 16-25 Aug. 1894, Topotype
Youngia diversifolia Led. var. lanciloba Freyn, Publication unknown
Europe: Dahuria, Nertschinsk, F. Karo, (Pl. Dahur. 262a), 1889, ? Type Collection Material
Yucca baccata Torr. var. vespertina McKelvey
U.S.A.: Nevada, Kyle Canyon, I.W. Clokey 7054, 10 May 1936, Paratype
Yucca baccata Torr. var. vespertina McKelvey, Yuccas of S.W. United States 45-46. 1938
U.S.A.: Nevada, Clark Co., Charleston Mts., I.W. Clokey 7074, 10 May 1936, Paratype
Zelkova serrata Makino f. stipulacea Hiyama, Publication unknown
Japan: Aomori Pref., Tsuta, Towada-machi, Kamikita-gun, T. Makino, 1928, ? Type Collection Material
Zephyranthes insularum Hume ex Moldenke, Herbertia 6: 123-125. 1939; Plant Life 8: 152. 1952
U.S.A.: Florida, Gainesville (cult.), H.N. Hume, 13 May 1935, Type Collection Material
Zieria murphyi Blakely, Austral. Nat. 10: 246. 1940
Australia: New South Wales, Gold Gully, Penrose, Murphy & Blakely 2580, 15 Oct. 1938, Isotype
Zinnia jugistyla P.G. Wilson, Kew Bull. 1958: 163. 1958
Mexico: Coyuca, G.B. Hinton 8033, 7-10-1935, Paratype
Zizania aquatica L. var. brevis N.C. Fassett, Rhod. 26: 157. 1924
Canada: Québec, Co. de Lévis, Lévis, S. Darbyshire 2031, 13 Aug. 1983, Topotype
Zizania palustris L. var. palustris f. purpurea Dore, Russell County, in Castor River, ca. 2 miles east of Embrum, Dore & Moore 10586, 21 Sept. 1949, Paratype
Zizania palustris L. var. palustris f. purpurea Dore, Nat. can. 103: 565. 1976 (1977)
Canada: Ontario, Russell Co., 2 mi. E of Embrum, Dore & Moore 10587, 21 Sept. 1949, Holotype
Zizania texana Hitchc., Jour. Wash. Acad. Sci. 23: 454. 1933
U.S.A.: Texas, San Marcos River, W.A. Silveus 2731, 31 May 1938, Topotype
Ziziphora dzhavakhishvilii Juz., Sched. Herb. Fl. U.R.S.S. 14 Fasc. 82: 67. 1957
U.S.S.R.: Georgia in vicin. opp. Bakuriana, G. Kiknadze, (sched 4090), 2 Oct. 1954, Isotype
Ziziphora taurica Marschall & Bieberstein, Flora Taurico-Caucas 1: 414. 1808
U.S.S.R.: Tauria, montis "Pertschem" prope "Sudak", A. Callier, June 1896 (Dörfler Herb. Norm. 3446), Topotype
Zygadenus fontanus Eastwood, Leafl. West. Bot. 2: 41. 1937
U.S.A.: California, Marin Co., Mt. Tamalpais, L.S. Rose 56102, 25 June 1956, Topotype