72 Rhodora [APRIL 
as large as in the European P. maritimum, in well developed plants 
4.5-5.3 mm. long, with faces 3-3.5 mm. broad. Its handsome white- 
rimmed flowers, too, are more obviously herbaceous below than in 
either P. glaucum or P. maritimum. This plant from the Gulf of St. 
Lawrence closely matches P. Raii Babington, a species of maritime 
sands from Scandinavia and Great Britain to northeastern France, 
and there seems no reason for not so calling it. 
But unfortunately the name Polygonum Raii (often spelled Rayi) 
has recently been set aside by many European botanists and has 
been replaced by the name P. Roberti Loiseleur; and following this 
European lead American students have begun to use the name E 
Roberti instead of P. Raii.! This understanding of the matter arose, 
apparently, from the fact that Meisner states in DeCandolle's Pro- 
dromus that material sent to him by Loiseleur was a mixture, but that 
the name properly belonged to P. aW.  Loiseleur's species was de- 
scribed from maritime sands of the Mediterranean, and since P. Rati, 
according to Rouy,? does not occur south of the shores of the English 
Channel (la Manche), it is hardly probable that P. Roberti, collected 
by Robert on the sands near Toulon, is identical with the northern 
plant. Furthermore, Rouy maintains? as P. Roberti a very distinct 
plant of the Mediterranean sands, with achenes only 2-3 mm. long. 
Under these circumstances it is apparently wiser to reinstate the name 
P. Raii for the northern plant to which it was originally applied. 
As already pointed out by Dr. Robinson,‘ the plant which for some 
time passed in America as Polygonum Rai, the plant of damp brackish 
or saline shores from southern Labrador to southern Maine, is an 
endemic American species, P. Fowleri. This species, which occurs 
also upon our northwestern coast (but apparently not from “New 
Brunswick to Vancouver Island," as stated by Small?) and was de- 
scribed by Meisner from Sitka as P. littorale, B. buxifolium 5 (as shown 
by the original material in the DeCandolle herbarium), lacks the 
glaucous hue of P. maritimum, P. glaucum, and P. Rai, ordinarily 
having a warm green or purplish tone. It is also quickly distinguished 
from those three species of the sands by its blunt or round-tipped 
1 See Robinson, Ruopona, iv. 67 (1902); Eames, ibid. xi. 93 (1909); Fernald, ibid. 
xiii. 138 (1911). 
? Rouy, Fl. Fr. xii. 110, 111 (1910). 3 Rouy, l. c. 
4 Robinson, Ruopora, l. c. 
5 Small, Mem. Dept. Bot. Columbia Col. i. 98 (1895). 
6 Meisner in DC. Prodr. xiv. 98 (1856). 
