93 
macropoda in size and general habit. Drummond’s Texan speci- 
men is represented by two plants, of which the sterile has the 
habit of JZ. macropoda and may belong to that species, but the 
fertile plant is a true mucronata form of MZ. vestita. Sterile _ 
specimens collected by Lemmon in the Sierra Valley are aquatic, 
and nearly smooth throughout. Specimens from Kansas, col- 
lected by Watson and by E.N. Plank, are very much reduced, 
being even smaller than Wright’s No. 2112, which Braun called 
var. minima. 
The distinctions which formerly separated JZ. mucronata can 
be maintained no longer, since they are sometimes united in the 
same plants, e. g., on Nicollet’s Devil’s Lake specimen, which 
Dr. Torrey originally referred to MZ. vestita, but which Braun 
placed in WW. mucronata. Specimens cultivated by Braun (coll. 
in Texas by E. Hall) and distributed to the Gray Herbarium as 
M. uncinata, do not agree in any particular with his own descrip- 
tion of that species, but are certainly his JZ. mucronata. 
Reverchon’s Texas specimens, distributed as IZ. mucronata, 
show a tendency to vary toward var. fenuzfolia in the narrower 
leaflets, suggesting the inconstancy of that variety. 
M. picta, Feé, is an enormous floating form, curiously marked 
on the under side of the leaflets by radiating ferruginous lines, 
giving it a unique appearance. Its true relations must be deter- 
mined by further observation. 
In order that some important particulars upon which the 
classification depends may be more fully established, it is desira- 
ble that collectors should pay especial attention to the following 
points : 
(1) In the same species note variations dependent upon — 
station ; that is, whether growing in mud, in marshy ground, in 
somewhat dry soil, in flooded regions or purely aquatic. Judging 
from the great amount of variation already noted resulting from 
station and environment, it is certainly desirable to note the ex- 
tent to which this variation is carried; certain it is, that the hairi- 
ness of the sporocarp, which often varies with age, cannot distin- 2 
guish one species from another, a principle that has not always 
been considered in descriptive works. : 
(2) Note specimens of MZ. uncinaza in mature fruit and de- 
