88 Rhodora (Marcu 
lished in the Flora Brasiliensis ! and reproduced in our figure 6, is of 
a very doubtful nature. If it is correct it must represent an other- 
wise unknown South American plant, which with its single row of 
carpels certainly can have nothing to do with our North American 
capitate-fruited chinodorus parvulus. If, however, we choose the 
other horn of the dilemma and assume that A/isma tenellum was in 
reality nothing but Æchinodorus parvulus, we are forced to the con- 
clusion that the figure in the Flora Brasiliensis is a mistake as to 
carpels. 
It is truly remarkable that another artist in preparing the figure for 
the Illustrated Flora has fallen into the same curious error and has 
produced a picture which in its contours, in the curve of each filament, 
and in the annular arrangement of the carpels, is so like a looking- 
glass replica of the one in the Flora Brasiliensis, that it would be 
hard to believe that it had not been mechanically reproduced, were 
we not informed in the preface of the Illustrated Flora that the cuts 
for the work were “all from original drawings." Unfortunately, the 
accompanying text is also neither accurate nor consistent. On page 
84 Alisma is said in the key to have the carpels in a ring, but it is 
described a few lines below as having the ovaries in one or several 
whorls. On page 85, although figured with achenes in a single ring, 
Alisma tenellum is described as having its achenes in several whorls. 
As we have seen, whatever may have been the case in the original A. 
tenellum, the achenes of the North American plant under discussion 
are neither in a ring nor in several whorls, but are spirally arranged 
in a head, and in this regard, as in every other, the plant is a good 
Echinodorus, the genus to which it has been uniformly referred in all 
editions of Gray's Manual and by the foreign specialists who have 
worked upon the group. 
There are in North America three species of Echinodorus, each of 
which is beautifully characterized by its carpels. In the little Æ. par- 
vulus, the rarest of the three, they are (as shown in figure 3) rounded 
at maturity, glandless and essentially beakless. In Æ. rostratus, 
Engelm. (Æ. cordifolius Griseb.) they are (as shown in figure 8) 
provided with a conspicuous erect beak and with two small amber 
colored glands on each lateral face near the summit, while in Z. radi- 
«ans, Engelm. (figure 7) the beak is incurved and there is a single 
Aili, pt. 1, t. £3, £. IT. 
