SPECIES OF ZANNICHELLIA. 263 
palustris. He neglected to mention, in the description of the genus, 
the number of the cells of the anthers, and spoke only of the general 
form of the stigma; so that his description was equally applicable to 
the two species of the Italian botanist, of which the one has two- 
celled anthers, with a crenulate stigma, the other, four-celled anthers 
and an entire stigma. At a later period, Willdenow distinguished 
them afresh ; he reserved the name of Z. palustris for the species 
with entire stigmas, and gave to the other the name of Z. dentata, 
founded on the character of the stigma. These species were adopted 
by Poiret in the Encyclopédie. Since then, it appears that the cha- 
racter of the anthers has been completely forgotten ; and because in 
the fig. 32 of Micheli the denticulation of the stigma is exaggerated, 
and it can only be seen with a powerful magnifier, and is especially 
difficult to be recognized in a dried state, the Z. dentata has disap- 
peared from the catalogues, not, indeed, without some appearance of 
reason, since Willdenow quotes improperly, as a synonyme of his Z. 
palustris, the t. 67 of Flora Danica, which belongs to the other 
species. 
We continued, therefore, to call every plant Z. palustris, Linn. in 
which we recognized the characters of the genus; and in this it can 
scarcely be said that we were wrong, since Linnzus had wilfully con- 
founded the two species of Micheli. Sprengel still makes mention of 
Z. dentata, but only as a variety of the common species. 
Since the Z. tuberosa, Loureiro, evidently forms part of another 
genus, the present has been reduced to a single species ; and that has 
happened to it which has occurred also to a great number of the Lin- 
nzan species which have been subjected to the more minute observa- 
tions of modern botanists, many of them having been divided, and the 
primitive character of the species become frequently that of a whole 
group. 
Beenninghausen (Prodom. Fl. Mon. p. 272) in 1824 recognized 
anew two species of Zannichellia, one of which he calls Z. repens, 
reserving to the other, which appears to have since become the Z. 
major, the name of palustris, after the figure of the Flora Danica. 
Nolte (see Reich. Fl. Exc. Genn. i, p.6) took this Z. repens for 
the Z. palustris, and distinguished two other species under the names 
of Z. maritima and polycarpa. Chamisso (Linnea, 1827) trans- 
ferred into this genus the Potamogeton contortum of Desfontaines. 
Salzman brought from Tangiers a plant which he arranged under the 
name of Z. disperma, a name essentially bad, since derived from two 
carpels. M. de Brébisson, in his Flora of Normandy, has recently 
