JOURNAL 
OF 
The New York Botanical Garden 
VoL. XII September, 1911. No. 141. 
THE USES OF THE CACTUSES.* 
The Cactaceae do not comprise a very large family, yet its 
members present a great variety, and constitute a very important 
feature in the world’s vegetation and landscapes. 
About 40 genera and 1,000 species are known. This audience 
is peculiarly favored by being privileged to see, in the green- 
houses and grounds of this Garden, what is undoubtedly the 
largest and most representative Gilection of these plants that 
has ever been brought together, more than 600 species being 
included. 
Cactuses are confined almost wholly to dry regions. In nearly 
all cases, these regions have a distinct rainy season, although it 
is sometimes very short indeed. During this rainy season, the 
plant lays in a supply of water sufficient to last it during the 
dry season that follows. For the performance of this function, 
the cactus, like the camel among animals, is specially constructed, 
a certain portion of its cells being so changed in form and habit 
that they are capable of taking in and holding securely a large 
amount of water. Tissue consisting of this sort of cell is called 
water storage tissue. Sometimes there is only a thin layer of this 
tissue under the surface of the stem, while at others, a large part 
of 
of such tissue is of this peculiar kind. € promptness with 
which the plant gorges itself with water as soon as the rains 
commence can be demonstrated by taking measurements of its 
*Lecture delivered at the New York Botanical Garden, July 22,1911. 
