1923] Fernald,— Distribution of Najas in northeastern America 107 
Lake of such maritime plants as Zannichellia, Ruppia, Triglochin 
maritima, Diplachne maritima Bicknell,’ Scirpus campestris, var. 
novae-angliae, Juncus Gerardi, Salicornia europaea, Chenopodium 
rubrum and Ranunculus Cymbalaria. 
N. FLEXILIS (Willd.) Rostk. & Schmidt. Morong’s very sweeping 
assertion, that N. flexilis “is widely diffused in North America, being 
found in Canada, from the Atlantic to the Pacific, and equally common 
in the United States and Mexico. It is as widely distributed in the 
Old World,’ needs severe pruning on all sides. The writer has 
before him not only the material in the Gray Herbarium and the 
herbarium of the New England Botanical Club, but that of the 
Missouri Botanical Garden (because of Englemann’s specia linterest 
in the genus) and of the University of Minnesota. In all this mass 
of material there are no clearly identifiable specimens from south of 
Maryland, Ohio, Indiana, Illnois and Iowa,’ while to the west of 
Iowa and Minnesota the species seems to be only in Idaho, Oregon, 
Washington and British Columbia.‘ Instead of being “as widely 
distributed in the Old World," Najas flexilis is there one of the 
most localized of species, being confined to 3 areas in Ireland,? 1 or 
2 in Scotland’ and a few in the Baltic region.” In fact the great 
rarity and restricted range of N. flexilis in Europe and the discovery 
there of numerous fossil beds containing fruits of the species* have 
made this plant one of unusual interest in Europe since it seems there 
to be a localized survivor of the formerly wide-spread North American 
flora which has become so generally obsolete in Europe. 
N. GUADALUPENSIS (Spreng. Morong is of much wider range 
northward than has been supposed. Bicknell has recorded it from 
1 Bicknell, Bull. Torr. Bot. Cl. xxxv. 195 (1908). 
2 Morong, 1. c. 60 (1893). : 
3 Rendle cites a specimen from Missouri but all the Missouri plants I have examined 
seem to be N. guadalupensis. 
4 This isolation in the northwestern states or British Columbia suggests other 
ranges, for example, that of Megalodonta Beckii (Torr.) Greene (Bidens Beckii Torr.): 
Quebec and Nova Scotia to New Jersey, west to Missouri and eastern Manitoba, 
also in Washington; or Potamogeton Robbinsii Oakes: New Brunswick to Maryland, 
west to Indiana, Michigan and Ontario, and in northwestern Wyoming, Idaho, 
Oregon, Washington and southern British Columbia. 
5 Praeger, Irish Top. Bot. 330 (1901). 
6 Watson, Top. Bot. 425 (1883); Praeger, Tourist's Fl. W. Ireland, 198 (1909). 
7 See Rendle, Trans. Linn. Soc. ser. 2, Bot. v. 404 (1899). 
8 See Rendle 1. c. 
