In this connection it is of interest to recall the fact that the 
so-called “monsoon dust” of the south Atlantic Ocean was at one 
time thought to be due to large quantities of pollen blown by the 
wind from the extensive forests of pines and other conifers along 
the coast of Brazil. It was supposed that the pollen settled on 
the ocean surface, and gave the peculiar yellowish or yellowish- 
green color to the water. Careful studies of this “dust” by 
Reinsch, a few years ago, showed, however, that the “monsoon 
dust” is in reality due to two or three species of blue-green 
algae, which accumulate in great quantities at intervals during 
the year. The phenomenon is sometimes referred to as “sea 
blossoming.” 
Residents and travelers in the Adirondack mountains are 
also familiar with the so-called “water-bloom,” or “blooming” 
of some of the numerous lakes of that region. The guides on 
the tract of the Adirondack League Club commonly refer to this 
appearance as the “flowering” or “blossoming” of the lakes. In 
1901 samples of water from a “blossoming” lake were collected 
by Mrs. Annie Morrill Smith, a membea of the Department of 
Botany of the Brooklyn Institute, and given to Dr. M. A. Howe, 
of the New York Botanical Garden, for determination. It was 
found that the “flowering” of the lakes is due, as in the case of 
the monsoon dust, not to floating pollen, but to large quantities 
of an alga, known in this case as Rivularia echinulata. 
A similar appearance, frequently observed in the glacial lakes 
of Minnesota and Wisconsin, has also been found to be due to 
the presence of an alga. The phenomenon known in Germany 
as IVasserbluethe , and in England, as the “breaking of the meres.” 
C. S. G. 
PLANTS NOW IN BLOOM 
In the local flora section of the Garden there are a few shrubs 
now flowering, among them the two species of chokeberry, Pyrus 
arbutifolia and Pyrus mela?iocarpa. Pyrus arbutifolia is 
much like the other species, except that it has red 
fruit, but both of them have white flowers. They are attract- 
ive, medium-sized bushes, situated on opposite sides of the 
grass aisle leading from the local flora valley to the Museum 
building. The red-fruited Pyrus arbutifolia is known from 
Staten Island, but not from Long Island. The other species is 
common everywhere. Another native shrub, on the east side of 
the valley is the beach plum ( Primus maritima ) common all 
along the ccast. It has white flowers followed in the summer by 
delicious, small, plum-like fruits, with a purple bloom, highly 
prized in making preserves. The much smaller sand plum 
{Prunus pumila) is near the other species, and is just passing 
out of flower. 
In the bog are two typically northern shrubs, famous for the 
beauty of their flowers. Rhodora ( Rhododendron canade?ise) with 
beautiful rose-pink flowers, is one of the most attractive shrubs 
