he? 
106 MISSOURI BOTANICAL GARDEN. 
Kennett, July 27, 1895, growing with Lemna Valdiviana, 
L. minor, Spirodela polyrrhiza, Wolfia Brasiliensis and 
Azolla Caroliniana; By Dr. O. Widmann, from the St. 
Francis river, October 5, 1895,— received at the Missouri 
Botanical Garden, adhering to the roots of Jussiaea repens. 
WOLFFIA LINGULATA, Hegelm. 
While on a brief visit in California during the past fall, 
one day late in September I discovered among other Lem- 
naceae growing in an irrigation canal an abundance of 
what afterward proved to be Wolffia lingulata, Hegelm. 
On October 7, 1895, I collected a large quantity of this 
mixture of aquatic plants which, with a little care, I was 
enabled to bring to St. Louis in good living condition and 
place in the Missouri Botanical Garden, where it has since 
continued to grow luxuriantly — affording abundant mate- 
rial for study, both for observations of growth habits and 
for anatomical investigations. 
Wolffia lingulata,Hegelm. is a much shorter and broader 
species than the foregoing and, as its name indicates, is tongue- 
shaped. Like W. gladiata it is curved in the direction of a 
band but, unlike it, is not curved edgewise. — It differs also in 
never forming the dense interlaced masses that gladiata 
does. This is impossible from the short and broad shape 
of the fronds. The young frond readily breaks away 
from its parent even before fully grown, so that no family 
grouping is ever found either. In the numberless speci- 
mens I have examined I have never yet found more than 
two * fronds united — the parent and offspring — though 
* These observations were made on normal plants with normal condi- 
tions surrounding them. Later I found in one of my fish-globes, where 
I have my plants growing, a few instances of three fronds united, but this 
seems to be due to the fact that the plants had not been disturbed for 
several weeks, for the slightest handling readily broke the three apart. 
The plants of this globe were not in a healthy condition either — being 
kept in another greenhouse of different temperature and humidity from 
the others. However, the rule as stated above holds true for the plants 
as they are found in their natural growth. 
