Rock Island Argus. (Rock Island, Ill.) 1893-1920, 1905-03-10

ments Used For Determining the
Various Phases of the Activities of
Desert Plants-When the Desert Is
q Garden OF Flowers.
DR.. W. A. Cannon, formerly in the
laboratory Of the New York botanical
gardens and now resident investigator
in charge of the Desert laboratory, near
Tucson, Ariz., was in New York re-
Gently. He described the first years
work of the laboratory, which was es-
tablished in 1903 to carry on special re-
searches upon the life. history and
physiology of desert plants, says the
New York Post
The site is on the north shoulder of
Table mountain, about 500 feet above
the town This was also the site OF the
prehistoric fortified town of Tucson,
where the village Indians sheltered and
protected themselves from the raids of
the Apaches. The village Indians, the
Papagos, are now widely scattered.
The fora of the laboratory tract is
very diverse, including plants which
grow on the mountain and those con-
fined to the mesa, or plain. Many of
these until recently were used by the
Indians and MeXicans in the cOnstruc-
ton OF their houses. Among them are
the giant cactus, the ribs of which
were used for the sides and roofs of
dwellings, and the ocotillo, which was
utilized for the same purpose. The
creosote bush was used for matching.
20 ia f,Ia that tho VILLAGE Indians
obtained their building materials from
the laboratory site.
AS it is the aim of the laboratory to
study the various phases Of the activ-
tiles of desert plants, with special ref
erence to the physical conditions to
which the plants are subjected, care
full record is being made of these ccsldi-
tons. This notes the changes IN tenn
perature, rainfall. relative humidity,
state of soil aud air and the brilliancy
Of the natural light, with their effect
upon the plants. For determining these
various conditions the laboratory has
especially delicate and ingenious self
recording instruments.
Although too short a time has elapsed
to permit the drawing of sweeping con-
illusions. many interesting facts have
been learned by this study. OF the
physical factors noted the amount of
water presented to the plant is the one
which influences its activity the most
profoundly. The existence of many
types of plants, such as ANIMALS, is di-
rectly controlled by the rainfall, and
the leaving and Towering of many
shrubs are controlled by the same fac
tor On the other hand, certain plants,
like the giant cactus, are apparently in
dependent Of the annual rains, as they
store up water in large quantities in
their own structure. 1t has been found
that the cactus known as the bisnaga
Is between 80 and % per cent water.
The estimate is made that II would
take two years average rainfall to sup
ply the space covered by the roots of
the plant with sufficient water to equal
the amount stored up in the plant it
self. Nature, 1t is explained, has pro-
vided that the plant shall absorb
enough water in wet years TO carry it
through dry seasons.
1t has been found that the transpira-
ton or evaporation Of water of some
of the plants is reduced in seasons of
drought to almost nothing, but when
the rains return the Transportation of
the desert plants equals and sometimes
exceeds the rate OF that of plants in
most regions. Transportation, said DR..
Cannon. Is an index of the activities of
all plants. and when the desert forms
have abundance of water growth is
quickened. They respond more prompt
ly TO the influence OF moisture than
plants in a moist climate. because they
have SO little time in which TO do it.
in the region of the laboratory there
are two seasons of rain-the summer
and the winter. 1t is in response to the
summer rains. when the temperature is
high, that vegetable activity is greater.
At this time the desert is covered with
a wonderful growth of plants. both an
nuals and perennials. and presents the
appearance of spring in more moist
climates. The flowers. many of them.
are large. striking and Of great beauty.
In many places they grow in such
masses that they can be seen for thirty
miles from elevations. this being par
ticularly true OF the MaripoSa lily and
California poppy. After the rains have
passed the annual vegetation dies with
in few days. the leaves Of many OF
the shrubs and perennials dry up and
fall off. and the country presents the
typical desert condition.
The study of plants is carried on
while they are in their naturs4S condi-
tions out OF doors. and the climsAe per
mits this study 10 be continued all the
year round. The desert plants in their
outdoor conditions are 10 be compared
with seedlings 10 be grown under
known conditions in a greenhouse now
in course OF construction at the Iabora-
tory.