300 PITTONIA. 
outline; those of strigosa were of a deeper green, strongly 
rugose, ovate in outline, each with a regular notch on one 
side, a little above the base, this corresponding to the furrow 
I had noticed on the seed ; those of rubella were reddish and 
rugose, like those of strigosa, but were of cuneate-oblong 
shape, with no notch, or any trace of it. 
In the course of the first four weeks of their development, 
any one would have called them different species. At the 
end of ten weeks one might again have doubted whether the 
two were not mere varieties or forms of the third; for even 
maritima, away from the sea, and upon ordinary dry ground, 
had largely lost its succulency, though its pale-green herbage 
"and broader leaflets still marked it as unlike its neighbors. 
This experience with these Hosackias illustrates how the 
most distinct and unquestionable species of plants may so 
closely simulate one another as to be indistinguishable in the 
maturer stages of growth ; and also how a great botanist like 
Nuttall, a man naturally endowed with the keenest percepti- 
bilities may, beyond all that, recognize by intuition as it 
were, species the essential visible or morphological charac- 
ters of which, lying away back in the embryonic stages of the 
plant’s development, he did not know. 
New or NoTEWORTHY SPECIES. 
M. 
POTENTILLA FRONDOSA. Stems clustered, erect or decum- 
bent, 11—3 feet high, conspicuously leafy throughout, the 
whole plant viseid-hirsute. leaves ample, the few radical 
with 3 or 4, the cauline with only 2 (rarely 3) pairs of leaflets + 
these oval or oblong, doubly incised but not deeply so, an 
