SALVINIA IN MINNESOTA 49 
“The reports of the occurrence of this species in 
Minnesota are based on its spontaneous appearance at 
the University Greenhouse in a tub of water in which 
had been placed a quantity of aquatic plants, muck, 
etc., collected in Sweeney Twin Lakes in the vicinity of 
Minneapolis. From this origin it has flourished in the 
greenhouses of the University for more than thirty 
years. It has never been found growing in the open 
in Minnesota, though a careful search has been made in 
the Sweeney Twin Lakes and elsewhere. At the time 
when it appeared a number of aquatic plants from out- 
side of the state were being handled in the greenhouse, 
and we are constrained to think that this plant was 
introduced along with some of them.” 
Shortly after the appearance of this publication, Dr. 
. L. Lyon of Honolulu, who formerly had worked 
extendivels with the pteridophytic collections of this 
herbarium, suggested to me that apparently the plant 
in question is not S. natans at all I had allowed the 
question to rest until Jast summer, when I received a 
letter from Mr. C. A. Weatherby, stating that an ex- 
amination of the Minnesota material in the Gray Her- 
barium indicated that it is S. awriculata Aubl., and 
suggesting that I examine all available Minnesota 
material, and send a note to the Fern Journal embody- 
ing my conclusions. 
An examination of both living plants and herbarium 
material has convinced me that it is all S. awriculata 
var. Olfersiana Klotzsch ex Baker. 8S. auriculata may 
be easily distinguished from S. natans by its nearly 
orbicular leaves, which are covered on the upper sur- 
face with clusters of trichomes raised on tall whitish 
papillae, which in the middle of the leaf are 2 mm. or 
more long, and by the numerous pinnate veins, which in 
O.R ahl and F. K. Butters, Reputed Minnesota Plants which 
arobably do not occur in the State. Minnesota Botanical Studies, 4: 
