Washington Flora Checklist
A Checklist of the Vascular Plants of Washington State
Hosted by the University of Washington Herbarium


Checklist » Hydrocharitaceae
Hydrocharitaceae   (Frogbit or Tapegrass or Waterweed Family)

Notes: FNA editors insisted on following Cronquist (1981) in recognizing Najadaceae, and the author's introduction to Najadaceae in FNA (Haynes 2000) protested Cronquist's treatment was outdated, citing recent papers investigating seed coat (Shaffer-Fehre 1991) and molecular relationships (Les & Haynes 1995). That evidence places Najadaceae within Hydrocharitaceae. Here we combine the two, as in JPM.

Family Synonyms:
» Najadaceae (Naiad Family, or Water-nymph Family)
» Vallisneriaceae

» Shaffer-Fehre, M. 1991. The position of Najas within the Alismatidae (Monocotyledones) in the light of new evidence from seed coat structures in the Hydrocharitoideae (Hydrocharitaceae). Bot. J. Linn. Soc. 107: 189-209.
» Les, D. H. & R. R. Haynes. 1995. Systematics of subclass Alismatidae: A synthesis of approaches. In: Rudall, P.J., et al., eds., 1995. Monocotyledons: Systematics and Evolution. 2 vols. Kew. Vol. 2, pp. 353-377.
» Haynes, R. R. 1977. The Najadaceae in the southeastern United States. J. Arnold Arbor. 58: 161--170.

Shaffer-Fehre, M. 1991. The endotegmen tuberculae: An account of little-known structures from the seed coat of the Hydrocharitoideae (Hydrocharitaceae) and Najas (Najadaceae). Bot. J. Linn. Soc. 107: 169--188.

Shaffer-Fehre, M. 1991b. The position of Najas within the subclass Alismatidae (Monocotyledones) in the light of new evidence from seed coat structures in the Hydrocharitoideae (Hydrocharitales). Bot. J. Linn. Soc. 107: 189--209.

Thorne, R. F. 1993c. Hydrocharitaceae. In: J. C. Hickman, ed. 1993. The Jepson Manual: Higher Plants of California. Berkeley, Los Angeles, and London. Pp. 1150--1151.

Family treatment authored by Peter F. Zika; last updated 10/21/2003 by Peter F. Zika
Taxon (native species in boldface) # Synonyms Common Names
Egeria densa Planch.   [FNA22] 1 Brazilian waterweed, waterweed, South American waterweed
Elodea canadensis Michx.   [FNA22, H&C] 2 Canadian, Rocky Mountain, or common waterweed
Elodea nuttallii (Planch.) H. St. John   [FNA22, H&C] 1 Nuttall's or western waterweed
Hydrilla verticillata (L. f.) Royle   [FNA22, not in H&C] 1 hydrilla, water thyme
Hydrocharis morsus-ranae L.   [Draft Revised H&C; FNA] 0 frogs's-bit
Limnobium laevigatum (Humb. & Bonpl. ex Willd.) Heine   [Draft Revised H&C] 0 frogbit
Najas canadensis Michx.    [Draft Revised H&C] 0 Canadian water nymph
Najas flexilis (Willd.) Rostk. & W.L.E. Schmidt   [FNA22, H&C] 2 slender or wavy water nymph, or slender naias
Najas guadalupensis (Spreng.) Magnus ssp. guadalupensis    [FNA22] 2 Guadalupe or common water nymph, Guadalupe naias
Vallisneria americana Michx.   [FNA22, H&C] 3 tapegrass, wild celery, eelgrass, American eelgrass

© 2010 University of Washington Herbarium,
Burke Museum of Natural History and Culture.
All Rights Reserved.
Box 355325, University of Washington,
Seattle, WA 98195-5325.