306 BOTANY. 
elegant little plants grew in patches of moss, in clefts of the rock, 
within reach of the spray from the lake. v 
As I was the first to discover this flower on Lake Michigan (in 
Wisconsin), so now, I believe, I am the first to find it in the state 
of Michigan, and thus have the pleasure of adding to its flora this — 
somewhat rare plant. I found it to-day (August 1, 1873), growing — 
rather abundantly on Grand Island, Michigan, along the high cliffs 
of red Potsdam sandstone overhanging Lake Superior. At this a 
date some of the plants are in full flower, others have gone to a 
seed, while a number have flower-buds still unexpanded. a 
I wish to call attention to the number of the sterile filaments in 
each set— so specific a distinction in this genus. Gray gives the 
number in P. parviflora as “about five in each set,” which corre 
sponds, I think, with other descriptions. In a large number ots 
specimens which I have to-day carefully examined, I find the — 
sterile filaments from six to nine, and occasionally eleven in each — 
set; but oftenest they are seven. This about agrees with my 
Lake Michigan plant. The flower is from five-eighths to three 
fourths of an inch broad; and the petals are. decidedly (generally wee 
one-fourth to one-third) longer than the calyx. The ova oa 
rather oblong leaves are somewhat heart-shaped at the base. 
These Lake Superior plants, growing mostly on the soft and dis- 
integrated sandstone, are of more luxuriant appearance than my 
specimens from Lake Michigan, which grew on limestone rock. I 
observed that matlike tufts of the plant, which had fallen from the 
beetling cliff, frequently took root and flourished on the beach be- 
low; though, doubtless, they are in such cases often swept away : 
by the fierce waves of Lake Superior. ts 
It seems to me that the Parnassias would make interesting 
garden plants, and prove easy of cultivation, Their cup-like 
flowers, of a delicate white finely veined with green, could not - 
to be considered ornamental; while the lengthy period of blos 
soming would be an additional recommendation. — HENRY Gur- 
MAN, Detroit, Michigan. 
Tue FRESH WATER AtG& or NORTH America.—Students of ‘ee 
fresh water algæ will find in the beautiful and interesting work © 
Dr. H. C. Wood, Jr., “ A Contribution to the History of the *™ 
Water Algæ of North America,” a ready means of identi i 
their specimens. It is a large quarto volume, with many 
