VEGETABLE PRODUCTIONS. 
To present a full and comprehensive- view of the botanical 
productions of the Isthmus, embracing as it does a variety of 
tropical and inter -tropical plants so valuable and numerous as to 
be unequalled within the same extent of territory, would exceed 
the usual limits of a work which is designed more as a record of 
mathematical results than a treatise on the natural resources of a 
country. JSor could the labor necessary for the proper classifica- 
tion here, of all the species be held justifiable under existing cir- 
cumstances, especially when we consider the fact that the inves- 
tigations of the commission were otherwise directed to subjects 
less secondary, and that on the Isthmus the names of plants vary 
with the numerous idioms of different sections. Care, neverthe- 
less, has been taken to prepare a list of some of the most valu- 
able species, from which some idea of the botanical riches of the 
country may be gleaned.* 
In a mountainous country like Mexico, having so great a diver- 
sity of elevation, temperature, and soil, the variety of indigenous 
products must be immense, and most of the plants cultivated in 
other parts of the globe find in that country situations adapted to 
their nature. It unites in itself the vegetation of North and South 
America, though it resembles that of the latter more especially. 
The distribution of plants on the Isthmus differs from that of 
Mexico in general, insomuch that the vegetation of the loftier 
table-lands is less distinctly marked. On the margins of the 
Gulf and the ocean are found the usual plants of inter-tropical 
shores, and upon the middle of the Isthmus, those families 
which vegetate favorably at elevations below 5000 feet within 
* Vide Botanical Tables, p. 197. 
