122 Rhodora [Jun 
Agardh). But with this characteristic fruit-form it cannot be satis- 
factorily placed with typical R. maritima, and with its long spiraling 
peduncle it is not referable to R. maritima, var. rostrata which it 
simulates in fruit. This long-peduncled plant is R. maritima var. 
longipes Hagstróm. Another common plant of North America, of 
possibly wider range than var. longipes is a very close match for the 
Old World material and plates of R. maritima, var. rostrata Agardh 
(R. rostellata Koch), having the semilunate strongly beaked fruit on 
long podogynes, but the peduncle only 1-3 cm. long and merely 
flexuous, not spiraling. This and the American plant with long 
spiraling peduncles (var. longipes) clearly intergrade; but so emphatic 
are the students of the group in Europe, that there R. rostellata never 
has elongate and spiraling peduncles, while the true R. maritima with 
subequilateral bluntish, not semilunate or eccentrically beaked, fruit 
always has such peduncles, that it seems right to follow Hagstróm in 
separating the var. longipes. 
This plant, var. longipes, simulating as it does true R. maritima (or 
spiralis) in its habit, but var. rostrata (R. rostellata) in its fruit, shows 
a characteristic which seems to pervade the entire series: namely, a 
strong tendency for the various characters of fruit and length of 
peduncle and of podogyne to reassert themselves in new combinations. 
It is doubtless this fact which has led to the ultra-conservative treat- 
ment in America which has heretofore made little or no attempt to 
define the various combinations of characters; but it is certainly 
most unsatisfactory, when we find in some of the natural areas of our 
coast a plant with peduncles uniformly less than 5 mm. long and 
podogynes essentially wanting, to be forced, on referring to an Ameri- 
can monograph, to crowd it into a species which is said to have the 
peduncle “a loosely coiled spiral.” 
Our study of Ruppia maritima, though by no means satisfactory to 
us, has shown that we have in North America several clearly definable 
variants or recombinations of the variable characters. Whether 
these or any of them should be regarded as species is a debatable 
question, but our present feeling is that they are best regarded as 
varieties. For the present we are so considering them and we offer 
the following synopsis, not with any assurance of its finality but with 
the hope that it will lead to the fuller and more critical observation 
and collection which the plants demand; and we are indebted to Mr. 
F. Schuyler Mathews for his assistance in preparing drawings to 
illustrate the plants discussed. 
