Vol. 1. No. 10.) BULLETIN OF TEE TORREY BOTANICAL CLUB. {New York, Vctober, 1870 
77, Spirodela, Schleiden, ilustrated.We have received commu- 
nications from Prof. Hegelmaier and Mr. Austin respecting the 
flowers and fruit of this plant, found last summer on Staten Island. 
It will be seen that it still remains a question whether this be the 
true Lemna polyrrhiza of Linneus. We are expecting soon to hear 
again from Prof. H., as in the first supply we sent him there was 
a deficiency of fruit. Mr. Austin illustrates his observations with 
a drawing. 
Tiibingen, Aug. 30th, 1870. 
Your discovery is of the highest interest for the knowledge of 
the Lemnacee, as the flowers and fruit of Spirodela rank among the 
greatest botanical rarities. I myself though working some years 
on these plants, and examining rich materials of them both living 
and dried, have never before seen the flowers and fruit; and, in 
fact, they have been seen and described only by a few authors. 
I immediately examined your plants as accurately as it was 
possible. In the vegetative parts there is no difference to be found 
from our Spirodela (Lemna) polyrrhiza, for the smallness of the 
fronds is certainly accidental, or rather is connected with the fer- 
tility of the plant. But the ovary, as I have found, is always one- 
ovuled in the stage of flower, and the fruit, as you state, one-seeded ; 
while the ovary of L. polyrrhiza is described decidedly, as being 
two-ovuled, by the authors who have seen it. I am, therefore, in- 
clined to judge that your plant must be considered as a different 
Species or subspecies of Spirodela...... The name of S. monosperma, 
[think would perhaps not be quite convenient, because it is very 
possible that in S. polyrrhiza, in the rare cases in which it may be 
fertile, only one of the two ovules is developed to a seed.......... 
F. Hecemaier. 
Closter, N. J., Oct. 10th, 1870. 
Me eis Dr. Engelmann writes, that both Griffith in India and 
Schleiden in Germany found this Lemna (polyrrhiza) binovulate, 
but that it matures but one seed; also that he found two ovules in 
one of our plants. I also have found two ovules in one example. 
The utricle is nearly round, biconvex, somewhat winged on the 
margins, abruptly beaked with a short, conic, truncate mouth, which 
1s slightly oblique (recurved), rather small for the size of the 
frond :—seed not quite filling the utricle, broadly oval, horizontal, 
with a black protruding hilum at the base—I saw no operculum 
at the apex, but did not look for it; half anatropous, composed of 
three distinct parts, of which only the central or albuminous portion 
18 easily separable; this contains the germ protruding from so 
apex, where it appears to be irregularly about four lobed ; oe sl 
pressure the germ appears to be slightly curved ingrid Pa “#8 
very thick, homogeneous, somewhat spongy;—the tner d if 
about as thick as the outer one, and appears to be composed o 
starch ;—the seed is somewhat flattened.—The frond is about 7 
(-9) nerved. The young frond issues from the same a as the 
frnit, and both above and over it. “ a ioe fae 2 
Since the above was in press we have received a note from Dr. 
Engelmann in which he says : “I whs delighted to-find x1 one of 
