STUDIES OF MEXICAN AND CENTRAL AMERICAN 
PLANTS—NO. 6." 
By J. ». Rose. 
INTRODUCTORY NOTES. 
This paper consists largely of descriptions of new species found in 
the process of naming large collections from Mexico, or in revising 
various genera of Mexican plants. It forms the sixth of this series 
and differs little, in its scope from previous ones. The collections 
studied have been chiefly those mentioned in my last paper, together 
with material received during the year 1906. A somewhat detailed 
account of my sixth journey through Mexico will not be out of place 
here. 
On July 26 I was authorized by Dr. R. Rathbun, Assistant Secretary 
in charge of the National Museum, to proceed to Mexico for the pur- 
pose of continuing my botanical explorations there. By the kindness 
of Dr. N. L. Britton, Director of the New York Botanical Garden, 
who placed a generous sum from the Garden funds at my disposal, I 
was enabled to take an assistant with me from Washington. I left 
Washington August 1 accompanied by my son, Joseph S. Rose, for 
the city of Mexico. En route for that city | made short stops at San 
Antonio and Laredo, Texas, where small collections were obtained. 
The City of Mexico was reached August 10, and for several days there- 
after I was engaged in establishing suitable headquarters in that city. 
Some time was also spent at the herbarium of the Instituto Medico 
Nacional, where every facility was given to help me in my work. <A 
short trip was also made during this time to the pedregal near Tlalpam, 
where a number of cacti and ferns were obtained. In the city of 
Mexico I was joined by Dr. C. G. Pringle and his assistant, Filemon 
Lozano; who accompanied me on various side trips. From the City of 
Mexico short trips were made to Cuernavaca, El Parque, Querétaro, 
Pachuca, and various places in the valley of Mexico, including one for 
water lilies to Lake Xochimileo. Toward the end of August I was 
joined in the city of Mexico by Dr. D. T. MacDougal and soon after- 
wards we changed our base to Tehuaciin, Puebla. Here we explored 
the limestone hills on both sides of the town, making large collections 
¢Continued from Vol. X, p. 182, of the Contributions. 
259 
