VOLUME LIII NUMBER 1 
Se eo 
MOLANICAL G,AZETTE- 
JANUARY 1g12 
MORPHOLOGY OF CERATOZAMIA 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 153 
CHARLES J. CHAMBERLAIN 
(WITH PLATE I AND SEVEN FIGURES) 
Southern Mexico, with its three genera of cycads (Dioon, 
Ceratozamia, and Zamia), is the principal cycad region of the 
western hemisphere. Two of these genera, Dioon and Cerato- 
zamia, may be confined to Mexico. Occasional reports indicate a 
wider distribution, but both genera are so commonly cultivated 
in parks, both in Mexico and farther south, that descriptions, even 
when supported by specimens, would need the addition of observa- 
tion in the field before habitats could be established. The first 
two descriptions of Dioon spinulosum, by DYER (1) and by EICHLER 
(2), were based upon cultivated specimens, and in the localities 
cited, Progreso and Cordoba, the species does not occur except 
in cultivation. 
Ceratozamia has been reported beyond Mexico, but whether 
from observation in the field or from cultivated specimens, is uncer- 
tain. It grows wild at Chavarrillo, where it is associated with 
Dioon edule, but the plants are only seedlings with 2 or 3 leaves, 
_ except on Monte Oscuro, where there are some specimens large 
enough to bear cones. Between Jalapa and the extinct crater of 
Naolinco is a beautiful valley, and on the Jalapa side of the moun- 
tains which rise from this valley, large fruiting plants of Cera- 
 tozamia are abundant, but are limited to a rather narrow vertical 
I 
