120 Rhodora [JULY 
our treatments of the group have depended more upon traditional 
interpretations than upon close study of the plants in the field. 
In Europe, Ruppia maritima has long been considered the type of a 
somewhat complex group of species, subspecies and varieties. By 
many authors of the present day four species, R. maritima L. in the 
strict sense (R. spiralis Dumort.), R. drepanensis Tineo, R. rostellata 
K och, and R. brachypus Gay, are recognized; while by others, Briquet, 
for instance, in his Prodrome de la Flore Corse, R. maritima is treated as 
the ty pe of an aggregate species with well defined subspecies; and by 
Ascherson & Graebner, in Engler's Pflanzenreich, a somewhat similar 
course is followed, with a confusing division of subspecies, proles, and 
varieties. 
In Ame ica the treatment has been more conservative, apparently 
too much "o. Early writers, such as Michaux, noted some divergence 
in the Am*erican and European plants, but all treated our eastern 
species as Ruppia maritima; and Nuttall in his description used a 
character which is by no means constant in American plants but is 
diagnostic of true A. maritima of Europe: “peduncle convolute- 
stretching or contracting according to the depth of water, after the 
manner of Vallisneria.” ? Gray stated, however, simply that “the 
spadix itself also [after flowering is] raised on an elongated thread- 
form peduncle," ? and in the description of the species in northeastern 
America said: "chiefly a narrowly leaved var. with strongly pointed 
fruit, approaching R. rostellàta, Koch." This statement stood in the 
Manual through five editions, but in the 6th edition, by Watson and 
Coulter, the reference to R. rostellata was dropped. In two recent 
American monographs of our Najadaceae, the spiraling peduncle 
again appears as a primary character. Thus in Morong's Naiadaceae 
of North America, under R. maritima we find: “In fruit the peduncles 
are greatly elongated, sometimes as much as 12 inches or even more 
.... The drupes vary a good deal in shape, usually simply conical 
with a short gibbous swelling at the base, sometimes with a strong 
spur-like projection and a curved outline, as in the form known in 
Europe as R. rostellata, Koch, which does not, however, differ other- 
wise from the type. Specimens with fruit of this shape are sent from 
1 Obs. Mea cum Europa omnino convenit; in eo tamen differens (si qua fides 
iconi optimi Geetneri) quod fructus ovoidens sit et in colliculum a stylo persistente 
desinat." — Michx. Fl. Bor.-Am. i. 102 (1803). 
? Nutt. Gen. i. 111 (1818). 
* Gray, Man. 454 (1848). 
