16 ADDISONIA 
other plants of arid regions, such as cacti and century plants. The 
leaves of all the species drop periodically, and the plant goes through 
a resting stage, when it needs little water in its cultivation. 
The relationship of the family is doubtful. By some it has been 
treated as a tribe of the tamarix family, while others have regarded 
it as a closely related but distinct family. To the writer its re- 
lationship appears to be with the phlox family, Polemoniaceae, as 
indicated some years ago in a general discussion of this subject 
(Bull. Torrey Club 30: 449, 1903). 
Some of the species are used as hedge plants, and for the formation 
of barriers. Some of the houses of the poorer classes of Mexicans 
are constructed by making the walls of branches of these plants 
and thatching the roof with other materials. The Mexican name 
ocotilla or ocotillo, a diminutive of ocote, a pine tree, is applied to 
resinous splints of pine wood which are used for torches and candles. 
The stems and splints of several species of Fouquieria, owing to the 
presence of resin and wax in the bark, are used for the same purposes, 
and the Mexicans apply to them the same name. ‘These splints 
are called ocotillas, and burn with an aromatic fragrance, being 
carried at funerals and used as candles in illuminating churches. 
The development of the spines, which are found on all known 
species of the genus, is interesting and peculiar. In the petioles 
of the primary leaves, which are produced on the new shoots, a 
hard tissue is formed, which, upon the withering and separation of 
the leaf-blades, remains as the spine; it is in the axils of these spines 
that the fascicles of secondary leaves appear. A detailed account, 
by Winifred J. Robinson, of the development of these spines 
was published in the Bulletin of the Torrey Botanical Club (31: 45. 
1904). 
GrorGE V. Nasa. 
EXPLANATION OF PLATE. Fig. 1.—Flowering branch. Fig. 2.—Portion of 
stem, with a leaf. Fig. 3—Flower just opened, the stamens not yet fully 
developed. Fig. 4.—Stamen. Fig. 5.—Style. 
